Literatura académica sobre el tema "Il gene MEF"
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Artículos de revistas sobre el tema "Il gene MEF"
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Marimón, José María, Adoración Valiente, María Ercibengoa, José M. García-Arenzana y Emilio Pérez-Trallero. "Erythromycin Resistance and Genetic Elements Carrying Macrolide Efflux Genes in Streptococcus agalactiae". Antimicrobial Agents and Chemotherapy 49, n.º 12 (diciembre de 2005): 5069–74. http://dx.doi.org/10.1128/aac.49.12.5069-5074.2005.
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ABSTRACT The macrolide resistance determinants and genetic elements carrying the mef(A) and mef(E) subclasses of the mef gene were studied with Streptococcus agalactiae isolated in 2003 and 2004 from 7,084 vaginorectal cultures performed to detect carrier pregnant women. The prevalence of carriage was 18% (1,276 isolates), and that of erythromycin resistance 11.0% (129 of the 1,171 isolates studied). erm(B), erm(A) subclass erm(TR), and the mef gene, either subclass mef(A) or mef(E), were found in 72 (55.8%), 41 (31.8%), and 12 (9.3%) erythromycin-resistant isolates, while 4 isolates had more than 1 erythromycin resistance gene. Of the 13 M-phenotype mef-containing erythromycin-resistant S. agalactiae isolates, 11 had the mef(E) subclass gene alone, one had both the mef(E) and the erm(TR) subclass genes, and one had the mef(A) subclass gene. mef(E) subclass genes were associated with the carrying element mega in 10 of the 12 mef(E)-containing strains, while the single mef(A) subclass gene found was associated with the genetic element Tn1207.3. The nonconjugative nature of the mega element and the clonal diversity of mef(E)-containing strains determined by pulsed-field gel electrophoresis suggest that transformation is the main mechanism through which this resistance gene is acquired.
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Mingoia, Marina, Manuela Vecchi, Ileana Cochetti, Emily Tili, Luca A. Vitali, Aldo Manzin, Pietro E. Varaldo y Maria Pia Montanari. "Composite Structure of Streptococcus pneumoniae Containing the Erythromycin Efflux Resistance Gene mef(I) and the Chloramphenicol Resistance Gene catQ". Antimicrobial Agents and Chemotherapy 51, n.º 11 (20 de agosto de 2007): 3983–87. http://dx.doi.org/10.1128/aac.00790-07.
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ABSTRACT In recent years mef genes, encoding efflux pumps responsible for M-type macrolide resistance, have been investigated extensively for streptococci. mef(I) is a recently described mef variant detected in particular isolates of Streptococcus pneumoniae instead of the more common mef(E) and mef(A). This study shows that mef(I) is located in a new composite genetic element, whose sequence was completely analyzed and the left and right junctions determined, demonstrating a unique genetic organization. The new composite structure (30,505 bp), designated the 5216IQ complex, consists of two halves: a left one (15,316 bp) formed by parts of the known transposons Tn5252 and Tn916, and a right one (15,115 bp) formed by a new fragment, designated the IQ element. While the defective Tn916 contained a silent tet(M) gene, the IQ element, ending with identical transposase genes on both sides and containing the mef(I) gene with an adjacent new msr(D) gene variant and a catQ chloramphenicol acetyltransferase gene, was completely different from the genetic elements carrying other mef genes in pneumococci. This is the first report demonstrating catQ in S. pneumoniae and showing its linkage with a mef gene. Analysis of the chromosomal region beyond the left junction revealed an organization more similar to that of S. pneumoniae strain TIGR4 than to that of strain R6. The 5216IQ complex was apparently nonmobile, with no detectable transfer of erythromycin resistance being obtained in repeated transformation and conjugation assays.
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Cochetti, Ileana, Manuela Vecchi, Marina Mingoia, Emily Tili, Maria R. Catania, Aldo Manzin, Pietro E. Varaldo y Maria Pia Montanari. "Molecular Characterization of Pneumococci with Efflux-Mediated Erythromycin Resistance and Identification of a Novel mef Gene Subclass, mef(I)". Antimicrobial Agents and Chemotherapy 49, n.º 12 (diciembre de 2005): 4999–5006. http://dx.doi.org/10.1128/aac.49.12.4999-5006.2005.
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ABSTRACT The molecular genetics of macrolide resistance were analyzed in 49 clinical pneumococci (including an “atypical” bile-insoluble strain currently assigned to the new species Streptococcus pseudopneumoniae) with efflux-mediated erythromycin resistance (M phenotype). All test strains had the mef gene, identified as mef(A) in 30 isolates and mef(E) in 19 isolates (including the S. pseudopneumoniae strain) on the basis of PCR-restriction fragment length polymorphism analysis. Twenty-eight of the 30 mef(A) isolates shared a pulsed-field gel electrophoresis (PFGE) type corresponding to the England14-9 clone. Of those isolates, 27 (20 belonging to serotype 14) yielded multilocus sequence type ST9, and one isolate yielded a new sequence type. The remaining two mef(A) isolates had different PFGE types and yielded an ST9 type and a new sequence type. Far greater heterogeneity was displayed by the 19 mef(E) isolates, which fell into 11 PFGE types, 12 serotypes (though not serotype 14), and 12 sequence types (including two new ones and an undetermined type for the S. pseudopneumoniae strain). In all mef(A) pneumococci, the mef element was a regular Tn1207.1 transposon, whereas of the mef(E) isolates, 17 carried the mega element and 2 exhibited a previously unreported organization, with no PCR evidence of the other open reading frames of mega. The mef gene of these two isolates, which did not match with the mef(E) gene of the mega element (93.6% homology) and which exhibited comparable homology (91.4%) to the mef(A) gene of the Tn1207.1 transposon, was identified as a novel mef gene variant and was designated mef(I). While penicillin-nonsusceptible isolates (three resistant isolates and one intermediate isolate) were all mef(E) strains, tetracycline resistance was also detected in three mef(A) isolates, due to the tet(M) gene carried by a Tn916-like transposon. A similar mechanism accounted for resistance in four of the five tetracycline-resistant isolates carrying mef(E), in three of which mega was inserted in the Tn916-like transposon, giving rise to the composite element Tn2009. In the fifth mef(E)-positive tetracycline-resistant isolate (the S. pseudopneumoniae strain), tetracycline resistance was due to the presence of the tet(O) gene, apparently unlinked to mef(E).
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Wierzbowski, Aleksandra K., Dave Boyd, Michael Mulvey, Daryl J. Hoban y George G. Zhanel. "Expression of the mef(E) Gene Encoding the Macrolide Efflux Pump Protein Increases in Streptococcus pneumoniae with Increasing Resistance to Macrolides". Antimicrobial Agents and Chemotherapy 49, n.º 11 (noviembre de 2005): 4635–40. http://dx.doi.org/10.1128/aac.49.11.4635-4640.2005.
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ABSTRACT Active macrolide efflux is a major mechanism of macrolide resistance in Streptococcus pneumoniae in many parts of the world, especially North America. In Canada, this active macrolide efflux in S. pneumoniae is predominantly due to acquisition of the mef(E) gene. In the present study, we assessed the mef(E) gene sequence as well as mef(E) expression in variety of low- and high-level macrolide-resistant, clindamycin-susceptible (M-phenotype) S. pneumoniae isolates (erythromycin MICs, 1 to 32 μg/ml; clindamycin MICs, ≤0.25 μg/ml). Southern blot hybridization with mef(E) probe and EcoRI digestion and relative real-time reverse transcription-PCR were performed to study the mef(E) gene copy number and expression. Induction of mef(E) expression was analyzed by Etest susceptibility testing pre- and postincubation with subinhibitory concentrations of erythromycin, clarithromycin, azithromycin, telithromycin, and clindamycin. The macrolide efflux gene, mef(E), was shown to be a single-copy gene in all 23 clinical S. pneumoniae isolates tested, and expression post-macrolide induction increased 4-, 6-, 20-, and 200-fold in isolates with increasing macrolide resistance (erythromycin MICs 2, 4, 8, and 32 μg/ml, respectively). Sequencing analysis of the macrolide efflux genetic assembly (mega) revealed that mef(E) had a 16-bp deletion 153 bp upstream of the putative start codon in all 23 isolates. A 119-bp intergenic region between mef(E) and mel was sequenced, and a 99-bp deletion was found in 11 of the 23 M-phenotype S. pneumoniae isolates compared to the published mega sequence. However, the mef(E) gene was fully conserved among both high- and low-level macrolide-resistant isolates. In conclusion, increased expression of mef(E) is associated with higher levels of macrolide resistance in macrolide-resistant S. pneumoniae.
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Cerdá Zolezzi, Paula, Leticia Millán Laplana, Carmen Rubio Calvo, Pilar Goñi Cepero, Melisa Canales Erazo y Rafael Gómez-Lus. "Molecular Basis of Resistance to Macrolides and Other Antibiotics in Commensal Viridans Group Streptococci and Gemella spp. and Transfer of Resistance Genes to Streptococcus pneumoniae". Antimicrobial Agents and Chemotherapy 48, n.º 9 (septiembre de 2004): 3462–67. http://dx.doi.org/10.1128/aac.48.9.3462-3467.2004.
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ABSTRACT We assessed the mechanisms of resistance to macrolide-lincosamide-streptogramin B (MLSB) antibiotics and related antibiotics in erythromycin-resistant viridans group streptococci (n = 164) and Gemella spp. (n = 28). The macrolide resistance phenotype was predominant (59.38%); all isolates with this phenotype carried the mef(A) or mef(E) gene, with mef(E) being predominant (95.36%). The erm(B) gene was always detected in strains with constitutive and inducible MLSB resistance and was combined with the mef(A/E) gene in 47.44% of isolates. None of the isolates carried the erm(A) subclass erm(TR), erm(A), or erm(C) genes. The mel gene was detected in all but four strains carrying the mef(A/E) gene. The tet(M) gene was found in 86.90% of tetracycline-resistant isolates and was strongly associated with the presence of the erm(B) gene. The catpC194 gene was detected in seven chloramphenicol-resistant Streptococcus mitis isolates, and the aph(3′)-III gene was detected in four viridans group streptococcal isolates with high-level kanamycin resistance. The intTn gene was found in all isolates with the erm(B), tet(M), aph(3′)-III, and catpC194 gene. The mef(E) and mel genes were successfully transferred from both groups of bacteria to Streptococcus pneumoniae R6 by transformation. Viridans group streptococci and Gemella spp. seem to be important reservoirs of resistance genes.
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Ando, Koji, Emi Matsuo, Kensuke Horio, Shinya Tominaga, Daisuke Imanishi, Yoshitaka Imaizumi, Hideki Tsushima et al. "Transcriptional Activity of MEF/ELF4 on the HDM2 Promoter Is Enhanced by the Mutation of the NPM1 Gene". Blood 116, n.º 21 (19 de noviembre de 2010): 179. http://dx.doi.org/10.1182/blood.v116.21.179.179.
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Abstract Abstract 179 Background: MEF/ELF4 belongs to an ETS family of transcription factors that has roles in hematopoietic stem cells (HSCs): in a Mef-null mouse model, HSC increased residence in G0 status of the cell cycle. It was also reported that Mef/Elf4 promoted the transformation of fibroblasts by inhibiting two major tumor suppressor pathways, the p53 and p16/Rb pathways, inducing the expression of the Mdm2 gene. Our previous study on AML samples showed that the expression of MEF/ELF4 was significantly lower in cases with t(8;21) and t(15;17) compared with those with normal karyotype (AML-NK). However, little has been investigated about the role of MEF/ELF4 in AML-NK. Objective: The aim of the present study is to elucidate how MEF/ELF4 works and is controlled in AML-NK. Methods: We identified the associated protein with MEF/ELF4 using the Tandem affinity purification (TAP) method followed by MASS analysis. Transforming activity of MEF/ELF4 was tested by colony-formation assay using NIH3T3 cells. The transcriptional activity of MEF/ELF4 and its binding to the HDM2 promoter region, with or without wild type NPM1 (wtNPM1) and its mutants (mutNPM1), were examined using luciferase analysis, EMSA and ChIP assay. We also examined the expression of MEF/ELF4 and HDM2 in CD34-positive AML-NK cells obtained from 22 patients. Results: Nucleophosmin (NPM1) was included in the twenty-six proteins that were found in the TAP analysis, and the direct binding between MEF/ELF4 and NPM1 was confirmed by immunoprecipitation, GST pull down, and in vitro translation assays. Transforming activity of MEF/ELF4 was decreased 3-fold by the overexpression of wild-type NPM1, whereas the activity was enhanced by mutNPM1. Transcriptional activity of MEF/ELF4 measured using luciferase assay (159-fold by arbitral unit) was increased by the co-expression of mutNPM1 (315-fold), and decreased by wtNPM1 (109-fold) (Figure1). Forced expression of siRNA for NPM1 enhanced the luciferase activity of MEF/ELF4. These results indicated that the transactivating activity of MEF/ELF4 was enhanced by mutNPM1, and decreased by wtNPM1. EMSA and ChIP assay for the HDM2 promoter demonstrated that MEF/ELF4 was bound to the specific binding sites of the HDM2 gene. wtNPM1 weakened the binding of MEF/ELF4 to the promoter of the HDM2 gene in EMSA and ChIP assay. However, co-expression of mutNPM1 increased its binding to the HDM2 promoter in ChIP assay (Figure2). These data suggested that NPM1 regulated the binding of MEF/ELF4 to the HDM2 promoter, which influenced the activity of MEF/ELF4. In clinical samples, AML-NK cells with the high expression of MEF/ELF4 showed significantly higher expression of HDM2 than those with the low expression of MEF/ELF4 (P=0.009). In AML-NK cases with the mutated-NPM1 gene, the expression of HDM2 was higher than those with the wild-type NPM1 (P=0.03). Conclusion: These data suggested that MEF/ELF4 activates the expression of the HDM2 gene under the influence of the mutational status of the NPM1 gene in AML-NK. Disclosures: No relevant conflicts of interest to declare.
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Cserjesi, P. y E. N. Olson. "Myogenin induces the myocyte-specific enhancer binding factor MEF-2 independently of other muscle-specific gene products". Molecular and Cellular Biology 11, n.º 10 (octubre de 1991): 4854–62. http://dx.doi.org/10.1128/mcb.11.10.4854-4862.1991.
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The myocyte-specific enhancer-binding factor MEF-2 is a nuclear factor that interacts with a conserved element in the muscle creatine kinase and myosin light-chain 1/3 enhancers (L. A. Gossett, D. J. Kelvin, E. A. Sternberg, and E. N. Olson, Mol. Cell. Biol. 9:5022-5033, 1989). We show in this study that MEF-2 is regulated by the myogenic regulatory factor myogenin and that mitogenic signals block this regulatory interaction. Induction of MEF-2 by myogenin occurs in transfected 10T1/2 cells that have been converted to myoblasts by myogenin, as well as in CV-1 kidney cells that do not activate the myogenic program in response to myogenin. Through mutagenesis of the MEF-2 site, we further defined the binding site requirements for MEF-2 and identified potential MEF-2 sites within numerous muscle-specific regulatory regions. The MEF-2 site was also found to bind a ubiquitous nuclear factor whose binding specificity was similar to but distinct from that of MEF-2. Our results reveal that MEF-2 is controlled, either directly or indirectly, by a myogenin-dependent regulatory pathway and suggest that growth factor signals suppress MEF-2 expression through repression of myogenin expression or activity. The ability of myogenin to induce MEF-2 activity in CV-1 cells, which do not activate downstream genes associated with terminal differentiation, also demonstrates that myogenin retains limited function within cell types that are nonpermissive for myogenesis and suggests that MEF-2 is regulated independently of other muscle-specific genes.
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Cserjesi, P. y E. N. Olson. "Myogenin induces the myocyte-specific enhancer binding factor MEF-2 independently of other muscle-specific gene products." Molecular and Cellular Biology 11, n.º 10 (octubre de 1991): 4854–62. http://dx.doi.org/10.1128/mcb.11.10.4854.
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The myocyte-specific enhancer-binding factor MEF-2 is a nuclear factor that interacts with a conserved element in the muscle creatine kinase and myosin light-chain 1/3 enhancers (L. A. Gossett, D. J. Kelvin, E. A. Sternberg, and E. N. Olson, Mol. Cell. Biol. 9:5022-5033, 1989). We show in this study that MEF-2 is regulated by the myogenic regulatory factor myogenin and that mitogenic signals block this regulatory interaction. Induction of MEF-2 by myogenin occurs in transfected 10T1/2 cells that have been converted to myoblasts by myogenin, as well as in CV-1 kidney cells that do not activate the myogenic program in response to myogenin. Through mutagenesis of the MEF-2 site, we further defined the binding site requirements for MEF-2 and identified potential MEF-2 sites within numerous muscle-specific regulatory regions. The MEF-2 site was also found to bind a ubiquitous nuclear factor whose binding specificity was similar to but distinct from that of MEF-2. Our results reveal that MEF-2 is controlled, either directly or indirectly, by a myogenin-dependent regulatory pathway and suggest that growth factor signals suppress MEF-2 expression through repression of myogenin expression or activity. The ability of myogenin to induce MEF-2 activity in CV-1 cells, which do not activate downstream genes associated with terminal differentiation, also demonstrates that myogenin retains limited function within cell types that are nonpermissive for myogenesis and suggests that MEF-2 is regulated independently of other muscle-specific genes.
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Cousin, Sydney, William L. H. Whittington y Marilyn C. Roberts. "Acquired Macrolide Resistance Genes in Pathogenic Neisseria spp. Isolated between 1940 and 1987". Antimicrobial Agents and Chemotherapy 47, n.º 12 (diciembre de 2003): 3877–80. http://dx.doi.org/10.1128/aac.47.12.3877-3880.2003.
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ABSTRACT Seventy-six Neisseria gonorrhoeae isolates, isolated between 1940 and 1987, and seven Neisseria meningitidis isolates, isolated between 1963 and 1987, were screened for the presence of acquired mef(A), erm(B), erm(C), and erm(F) genes by using DNA-DNA hybridization, PCR analysis, and sequencing. The mef(A), erm(B), and erm(F) genes were all identified in a 1955 N. gonorrhoeae isolate, while the erm(C) gene was identified in a 1963 N. gonorrhoeae isolate. Similarly, both the mef(A) and erm(F) genes were identified in a 1963 N. meningitidis isolate. All four acquired genes were found in later isolates of both species. The mef(A) gene from a 1975 N. gonorrhoeae isolate was sequenced and had 100% DNA and amino acid identity with the mef(A) gene from a 1990s Streptococcus pneumoniae isolate. Selected early isolates were able to transfer their acquired genes to an Enterococcus faecalis recipient, suggesting that these genes are associated with conjugative transposons. These isolates are the oldest of any species to carry the mef(A) gene and among the oldest to carry these erm genes.
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Hidaka, K., I. Yamamoto, Y. Arai y T. Mukai. "The MEF-3 motif is required for MEF-2-mediated skeletal muscle-specific induction of the rat aldolase A gene". Molecular and Cellular Biology 13, n.º 10 (octubre de 1993): 6469–78. http://dx.doi.org/10.1128/mcb.13.10.6469-6478.1993.
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The rat aldolase A gene contains two alternative promoters and two alternative first exons. The distal promoter M is expressed at a high level only in skeletal muscle. Previous in vitro transfection studies identified the region from -202 to -85 as an enhancer that is responsible for dramatic activation during the differentiation of chicken primary myoblasts. This enhancer contains an A/T-rich sequence resembling the MEF-2 motif, which is an important element of muscle enhancers and promoters. In this study, we demonstrate that the MEF-2 sequence is essential but not sufficient for the activity of the enhancer. Another region required for the activity was recognized by a nuclear factor, tentatively named MAF1. MAF1 was found in both muscle cells and nonmuscle cells, and MAF1 from both cell types was indistinguishable by gel retardation and DNase I footprint experiments. The sequence required for MAF1 binding is very similar to the MEF-3 motif, which is an element of the skeletal muscle-specific enhancer of the cardiac troponin C gene. Because MAF1 and MEF-3 are closely related in both recognition sequence and distribution, MAF1 and MEF-3 probably represent the same nuclear factor which may play an important role in muscle gene transcription. Thus, the muscle-specific induction of the aldolase A gene is governed by muscle-specific MEF-2 and existing MEF-3 (MAF1).
Tesis sobre el tema "Il gene MEF"
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Shen, Yang. "A high-resolution genetic map of human chromosome 16 and localization of the MEF gene /". Title page, contents and summary only, 1994. http://web4.library.adelaide.edu.au/theses/09PH/09phs546.pdf.
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Thesis (Ph. D.)--University of Adelaide, Dept. of Paediatrics, Women's and Children's Hospital, 1994.Copies of author's previously published articles inserted. Includes bibliographical references.
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Accardo, Silvia <1976>. "Il gene plasmidico orf5 e il gene pmpD di Chlamydia trachomatis". Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2010. http://amsdottorato.unibo.it/2911/1/ACCARDO_SILVIA_TESI.pdf.
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Accardo, Silvia <1976>. "Il gene plasmidico orf5 e il gene pmpD di Chlamydia trachomatis". Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2010. http://amsdottorato.unibo.it/2911/.
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Knigge, Anja, Nora Klöting, Michael R. Schön, Arne Dietrich, Mathias Fasshauer, Daniel Gärtner, Tobias Lohmann et al. "ADCY5 gene expression in adipose tissue is related to obesity in men and mice". Universitätsbibliothek Leipzig, 2015. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-169954.
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Genome wide association studies revealed an association of the single nucleotide polymorphism rs11708067 within the ADCY5 gene—encoding adenylate cyclase 5—with increased type 2 diabetes (T2D) risk and higher fasting glucose. However, it remains unclear whether the association between ADCY5 variants and glycemic traits may involve adipose tissue (AT) related mechanisms. We therefore tested the hypothesis that ADCY5 mRNA expression in human and mouse AT is related to obesity, fat distribution, T2D in humans and high fat diet (HFD) in mice. We measured ADCY5 mRNA expression in paired samples of visceral and subcutaneous adipose tissue from 244 individuals with a wide range of body weight and parameters of hyperglycemia, which have been genotyped for rs11708067. In addition, AT ADCY5 mRNA was assessed in C57BL/6NTac which underwent a 10 weeks standard
chow (n = 6) or high fat diet (HFD, n = 6). In humans, visceral ADCY5 expression is significantly higher in obese compared to lean individuals. ADCY5 expression correlates with BMI, body fat mass, circulating leptin, fat distribution, waist and hip circumference, but not with fasting plasma glucose and HbA1c. Adcy5 expression in mouse AT is significantly
higher after a HFD compared to chow (p<0.05). Importantly, rs11708067 is not associated with ADCY5 mRNA expression levels in either fat depot in any of the genetic models tested. Our results suggest that changes in AT ADCY5 expression are related to obesity and fat distribution, but not with impaired glucose metabolism and T2D. However, altered ADCY5 expression in AT does not seem to be the mechanism underlying the association between rs11708067 and increased T2D risk.
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Clements, Andrew R. N. "The regulation of globin gene expression". Thesis, University of Oxford, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.365687.
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Tourlaki, Athanasia <1973>. "The KIT gene in familial mastocytosis". Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2013. http://amsdottorato.unibo.it/5590/1/Tourlaki_Athanasia_tesi.pdf.
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Familial cutaneous mastocytosis is an exceptional condition of unknown etiology. In this study we report the largest series of patients with familial cutaneous mastocytosis without other manifestations (18 affected subjects from seven unrelated families), and we investigate the role of germ-line KIT mutations in the pathogenesis of the disease. The mean age at onset was 5.4 years (range from birth to 22 years), and the clinical behavior was variable over a mean follow up period of 15.1 years (range 2-36): improvement in seven, stability in eight and worsening in the remaining three patients. The pattern of inheritance was compatible with an autosomal dominant trait with incomplete penetrance; a female preponderance (14 females vs 4 males, ratio 3.5:1) was noted; among the six women who have been pregnant at least once, three experienced important clinical changes during pregnancy. No germ-line mutation was found in the exons 10, 11, and 17 of the KIT proto-oncogene, which are the most commonly mutated exons in sporadic mastocytosis. However, in the majority of affected subjects we found the Met541Leu polymorphic variant of the KIT gene, which seems to confer a growth advantage to mast cells in vitro. This observation further suggests that the Met541Leu may be a predisposing factor of cutaneous mastocytosis, although it seems to be neither necessary nor sufficient for the development of the disease.
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Tourlaki, Athanasia <1973>. "The KIT gene in familial mastocytosis". Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2013. http://amsdottorato.unibo.it/5590/.
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Familial cutaneous mastocytosis is an exceptional condition of unknown etiology. In this study we report the largest series of patients with familial cutaneous mastocytosis without other manifestations (18 affected subjects from seven unrelated families), and we investigate the role of germ-line KIT mutations in the pathogenesis of the disease. The mean age at onset was 5.4 years (range from birth to 22 years), and the clinical behavior was variable over a mean follow up period of 15.1 years (range 2-36): improvement in seven, stability in eight and worsening in the remaining three patients. The pattern of inheritance was compatible with an autosomal dominant trait with incomplete penetrance; a female preponderance (14 females vs 4 males, ratio 3.5:1) was noted; among the six women who have been pregnant at least once, three experienced important clinical changes during pregnancy. No germ-line mutation was found in the exons 10, 11, and 17 of the KIT proto-oncogene, which are the most commonly mutated exons in sporadic mastocytosis. However, in the majority of affected subjects we found the Met541Leu polymorphic variant of the KIT gene, which seems to confer a growth advantage to mast cells in vitro. This observation further suggests that the Met541Leu may be a predisposing factor of cutaneous mastocytosis, although it seems to be neither necessary nor sufficient for the development of the disease.
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Aramini, Beatrice <1979>. "Role of SP-A gene polymorphism in lung transplantation". Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2011. http://amsdottorato.unibo.it/3634/1/aramini_beatrice_tesi.pdf.
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Lung transplantation is a widely accepted therapeutic option for end stage lung disease. Clinical outcome is yet challenged by primary graft failure responsible for the majority of the early mortality, by chronic allograft dysfunction and chronic rejection accounting for more than 30% of deaths after the third postoperative year. Pulmonary surfactant proteins (SP) A, B, C and D are one of the first host defense mechanisms the lung can mount. SP-A in particular, produced by the type II pneumocytes, is active in the innate and adaptive immune system being an opsonin, but also regulating the macrophage and lymphocyte response. The main hypothesis for this project is that pulmonary surfactant protein A polymorphism may determine the early and long term lung allograft survival. Of note SP-A biologic activity seems to be genetically determined and SP-A polymorphisms have been associated to various lung disease. The two SP-A genes SP-A1 and SP-A2 have several polymorphisms within the coding region, SP-A1 (6A, 6A2-20), and SP-A2(1A, 1A0-13). The SP-A gene expression is regulated by cAMP, TTF-1 and glucocorticoids. In vitro studies have indicated that SP-A1 and SP-A2 gene variants may have a variable response to glucocorticoids. We proposed to determine if SP-A gene polymorphism predicts primary graft dysfunction and/or chronic lung allograft dysfunction and if SP-A may serve as a biomarker of lung allograft dysfunction. We also proposed to study the interaction between immunosuppressive drugs and SP-A expression and determine whether this is dependent on SP-A polymorphisms. This study will generate novel information improving our understanding of lung allograft dysfunction. It is conceivable that the information will stimulate the interest for a multi centre study to investigate if SP-A polymorphism may be integrated in the donor lung selection criteria and/or to implement post transplant tailored immunosuppression.
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Aramini, Beatrice <1979>. "Role of SP-A gene polymorphism in lung transplantation". Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2011. http://amsdottorato.unibo.it/3634/.
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Lung transplantation is a widely accepted therapeutic option for end stage lung disease. Clinical outcome is yet challenged by primary graft failure responsible for the majority of the early mortality, by chronic allograft dysfunction and chronic rejection accounting for more than 30% of deaths after the third postoperative year. Pulmonary surfactant proteins (SP) A, B, C and D are one of the first host defense mechanisms the lung can mount. SP-A in particular, produced by the type II pneumocytes, is active in the innate and adaptive immune system being an opsonin, but also regulating the macrophage and lymphocyte response. The main hypothesis for this project is that pulmonary surfactant protein A polymorphism may determine the early and long term lung allograft survival. Of note SP-A biologic activity seems to be genetically determined and SP-A polymorphisms have been associated to various lung disease. The two SP-A genes SP-A1 and SP-A2 have several polymorphisms within the coding region, SP-A1 (6A, 6A2-20), and SP-A2(1A, 1A0-13). The SP-A gene expression is regulated by cAMP, TTF-1 and glucocorticoids. In vitro studies have indicated that SP-A1 and SP-A2 gene variants may have a variable response to glucocorticoids. We proposed to determine if SP-A gene polymorphism predicts primary graft dysfunction and/or chronic lung allograft dysfunction and if SP-A may serve as a biomarker of lung allograft dysfunction. We also proposed to study the interaction between immunosuppressive drugs and SP-A expression and determine whether this is dependent on SP-A polymorphisms. This study will generate novel information improving our understanding of lung allograft dysfunction. It is conceivable that the information will stimulate the interest for a multi centre study to investigate if SP-A polymorphism may be integrated in the donor lung selection criteria and/or to implement post transplant tailored immunosuppression.
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SATTA, STEFANIA. "Studio del gene AHSP nelle β-Talassemie". Doctoral thesis, Università degli Studi di Cagliari, 2007. http://hdl.handle.net/11584/265981.
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Objective: To establish whether AHSP might have a role in modifying the clinical severity of beta-thalassemia.
Background: The severity of beta-thalassemia reflects the degree of globin chain imbalance and the excess of free alpha-globin chains that precipitate and cause oxidative damage in red cell precursors, inducing their premature destruction (ineffective erythropoiesis). AHSP is an abundant erythroid-specific protein that binds specifically to free alpha-globin and prevents its precipitation in vitro. It has been demonstrated in the animal model that AHSP is required for normal haemoglobin production and that it acts as a chaperone, to prevent the harmful aggregation of alpha-globin during normal erythroid development and in diseases with globin chain imbalance.
Patients and methods: AHSP gene (~1.4 Kb) and its promoter region was directly sequenced from PCR amplified DNA on ABI PRISM 3100, in 19 thalassemia intermedia and 14 thalassemia major patients with similar genetic characteristics (beta39/beta39, 3 or 4 alpha-globin genes and I-II or II-II haplotype according to Orkin et al).
Results: No nucleotide mutation that might alter the structure and function of AHSP was identified. We found in the large majority of the cases the same haplotypes with the same frequencies described in S/E Asia (Viprakasit et al., Blood 2004). No difference has been found in the haplotype frequencies between the beta-thalassemia major and intermedia patients.
Conclusion: We did not find mutations or specific association between haplotype of AHSP and disease severity in these patients, suggesting that AHSP is not a disease modifier in Sardinian beta-thalassemia patients.
Libros sobre el tema "Il gene MEF"
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Nussbaum, Robert L. Thompson & Thompson gene tica me dica. 7a ed. Rio de Janeiro: Saunders Elsevier, 2008.
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Een gang met gele deuren. Houten: Van Holkema & Warendorf, 2007.
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David, Sankoff y Nadeau J. H, eds. Comparative genomics: Empirical and analytical approaches to gene order dynamics, map alignment and the evolution of gene families. Dordrecht: Kluwer Academic, 2000.
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Geen rede mee te rijmen: Geschiedenis van de psychiatrie. Warnsveld: Lannoo, 2011.
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Michaud, Josélito. Dans mes yeux à moi: Récit. Montréal: Libre expression, 2011.
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Michaud, Josélito. Dans mes yeux à moi: Récit. Montréal]: Édition du Club Québec loisirs, 2011.
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Ellenbroek, Willem, Trix Broekmans y Thijs Wierema. De Man met het gele koffertje: Wim Wennekes 1948-2001. Amsterdam: Lubberhuizen, 2002.
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Geen leven zonder vriendschap: Over mensen met een ernstige beperking. Zoetermeer: Meinema, 2010.
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Vandenhole, F. Inventaris van veilingcatalogi, 1615-1914: Met topografische, alfabetische en inhoudsindexen. Gent: Rijksuniversiteit, Centrale Bibliotheek, 1987.
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McCann, Shaun R. Molecules, genes, and gene therapy. Oxford University Press, 2016. http://dx.doi.org/10.1093/med/9780198717607.003.0009.
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The twenty-first century has brought many innovations in haematology, with improved diagnostic technology, which may inform treatment choices for malignant diseases, and a better understanding of the genetics and/or epigenetics underlying many diseases. Unfortunately, the aetiology of most of these diseases still eludes us, and some common diseases such as sickle cell disease await simple, inexpensive, and widely available curative treatment. For reasons that are often obscure, some diseases have become fashionable and attract large research financial backing, whereas some do not. With the advent of advanced technology and an improved understanding of disease mechanisms, most haematological malignancies should enjoy the same success as the treatment of childhood acute lymphoblastic leukaemia and chronic myeloid leukaemia.
Capítulos de libros sobre el tema "Il gene MEF"
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Schratzberger, P. y Jeffrey M. Isner. "Angiogenesis and gene therapy". En From Molecule to Men, 221–32. Heidelberg: Steinkopff, 2000. http://dx.doi.org/10.1007/978-3-642-57724-6_19.
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Charron, Philippe y Carole Maupain. "Genetics of cardiomyopathies: hypertrophic cardiomyopathy". En ESC CardioMed, 688–91. Oxford University Press, 2018. http://dx.doi.org/10.1093/med/9780198784906.003.0154.
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Hypertrophic cardiomyopathy is characterized by the presence of increased left ventricular wall thickness that is not solely explained by abnormal loading conditions (such as hypertension or valvular disease). Hypertrophic cardiomyopathy is a genetic disease, usually with an autosomal dominant inheritance. About 35–60% of patients with hypertrophic cardiomyopathy carry a pathogenic mutation in sarcomeric protein genes. Most mutations are observed in genes encoding beta-myosin heavy chain (MYH7), cardiac myosin binding protein C (MYBPC3), or cardiac troponin T (TNNT2). Non-sarcomeric genetic causes exist, especially in children (Pompe disease, Noonan syndrome, or Friedreich ataxia). In adults, non-sarcomeric genetic causes include metabolic storage diseases such as Danon disease (LAMP2 gene), Fabry disease (GLA gene), left ventricular hypertrophy associated with Wolff–Parkinson–White syndrome (PRKAG2 gene), familial amyloidosis (TTR gene), and mitochondrial cardiomyopathies.
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Dooren, Sonia Van, Dorien Daneels, Gudrun Pappaert, Maryse Bonduelle y Pedro Brugada. "Monogenic and oligogenic cardiovascular diseases: genetics of arrhythmias—Brugada syndrome". En ESC CardioMed, 679–82. Oxford University Press, 2018. http://dx.doi.org/10.1093/med/9780198784906.003.0151.
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The heritable arrhythmogenic disorder Brugada syndrome (BrS), a cardiac ion channelopathy first described in 1992, is inherited as an autosomal dominant trait characterized by incomplete penetrance, variable expression, and phenotypic overlap. These characteristics all complicate the elucidation of the underlying molecular genetic pathway. Clearly, SCN5A, the gene encoding the pore-forming alpha subunit of the cardiac sodium channel, is the major susceptibility gene associated with BrS: 20–30% of BrS patients harbour pathogenic variants in this gene and BrS patients have a more than eight times higher burden of rare variants in this gene compared to controls. Rare pathogenic variants have also been reported in several sodium, potassium, and calcium channel genes, pacemaker genes, and sodium channel interacting genes. Given the minor collective contribution of these additional BrS-associated genes to the total genetic diagnostic yield, the hypothesis has been raised that other (genetic) determinants are involved. Indeed, the monogenic nature of BrS has been questioned and more support has recently been gained for the hypothesis of a complex inheritance based on genome-wide and gene panel studies. Probably, the BrS inheritance pattern is a continuum ranging from a monogenic, over an oligogenic towards even a polygenic spectrum. This, however, further impedes the interpretation of the contribution of (likely) pathogenic variants to the phenotype and urges for a cautious policy in a prenatal and preimplantation genetic diagnostic context: in many cases disease prevention will imply a risk reduction instead of an elimination of disease (development).
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Gavrilova, Ralitza H. "Patterns of Inheritance in Neurogenetic Disease". En Mayo Clinic Neurology Board Review, editado por Kelly D. Flemming, 233–37. Oxford University Press, 2021. http://dx.doi.org/10.1093/med/9780197512166.003.0029.
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The human genome consists of approximately 22,000 genes that are encoded within the nuclear DNA and embedded in the chromosome. Mitochondria are the only cytoplasmic organelles that have their own DNA. Nuclear gene disorders and mitochondrial inheritance are discussed in this chapter. Nuclear gene disorders follow the patterns of inheritance originally described by Gregor Mendel. They often are referred to as single-gene disorders because 1 or more alleles of only 1 locus are the major determinants of phenotype.
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Tavassoli, Mahvash y Francesco Pezzella. "Oncogenesis and tumour suppression". En Oxford Textbook of Cancer Biology, editado por Francesco Pezzella, Mahvash Tavassoli y David J. Kerr, 136–54. Oxford University Press, 2019. http://dx.doi.org/10.1093/med/9780198779452.003.0011.
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Two sets of genes are among the major driver of tumours, both malignant and benign: the oncogenes and the tumour suppressor genes. Oncogene refers to a gene that encodes for a protein (oncoprotein) in which excessive and unregulated activity can transform a normal cell into a cancer cell. As it is necessary for just one of the two gene copies to be abnormal, oncogenesis is defined as dominant. Tumour suppressor genes are known for their roles in inhibiting cell growth and have antitumour effects. According to the classic model, growth suppressor genes are recessive and therefore both copies have to be inactivated in order for an effect to be seen. Exception however occurs! Recently also non-coding mRNAs (i.e. an mRNA that is not translated into a protein) have been found to be able to induce oncogenic and suppressive effects. Finally, both some genes and some non-coding mRNA are able, in certain cellular contexts, to behave both as both an oncogenic and a suppressive factor.
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Menconi, Francesca, Terry F. Davies y Yaron Tomer. "Genetic factors relating to the thyroid with emphasis on complex diseases". En Oxford Textbook of Endocrinology and Diabetes, 371–85. Oxford University Press, 2011. http://dx.doi.org/10.1093/med/9780199235292.003.3084.
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The nucleus of each human cell encodes approximately 30 000 genes. A large fraction of the genes in each individual exist in a form that can vary between individuals. These variable genetic forms are termed polymorphisms, and they account for much of the normal variation in body traits, such as height and hair colour. The genetic information encoded in the DNA is stored on the chromosomes and each somatic cell contains 46 chromosomes (22 autosomes and two sex chromosomes), arranged in 23 pairs, one of each derived from each parent. Since each individual inherits two copies of each chromosome (for autosomes), one from each parent, there are also two copies of each gene. The chromosomal location of a gene is termed the locus of the gene. When the gene in a certain locus exists in two or more forms, these variants of the gene are termed alleles. When an individual’s two alleles at a locus are identical, that individual is said to be homozygous at that locus, and when the two alleles are different, the individual is a heterozygote. Female somatic cells contain two X chromosomes, whereas male somatic cells contain only one X chromosome. Nevertheless, the activity of genes coded for by the X chromosome is no higher in females than in males. This is due to inactivation of most of the genes on one of the two X chromosomes. Thus, in female somatic cells only one X chromosome gene is expressed, and this process of suppression is called X-chromosome inactivation. X-chromosome inactivation occurs early in embryonic life and, thereafter, in each cell either the maternal or paternal chromosome is inactivated. This results in a tissue mosaic of paternally and maternally expressed X-chromosomal alleles, with an average of 1:1 distribution. As a result, a female who is heterozygous for an X-linked gene will show a mosaic-like distribution of cells expressing either one of the two alleles. Recently X-inactivation has been postulated to play a role in autoimmune diseases and may help explain the female preponderance of autoimmune diseases (see below).
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Mogil, Jeffrey S. "Genetics and pain in childhood". En Oxford Textbook of Pediatric Pain, editado por Bonnie J. Stevens, Gareth Hathway y William T. Zempsky, 79–86. Oxford University Press, 2021. http://dx.doi.org/10.1093/med/9780198818762.003.0009.
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Genomic and other “omic” approaches are now routinely applied to the study of pain. Some of these investigations have utilized pediatric populations. This review describes what is currently known about the heritability of pain in children (from twin studies), genes relevant to pain in children (from single-gene mutations, candidate gene, and genome-wide association studies), and the application of newer techniques, such as epigenomics, to pediatric pain.
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Thapar, Anita y Peter McGuffin. "Quantitative genetics". En New Oxford Textbook of Psychiatry, 212–22. Oxford University Press, 2012. http://dx.doi.org/10.1093/med/9780199696758.003.0028.
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In this chapter the authors consider the theoretical basis of inheritance and possible sources of phenotypic variation and familial resemblance. The investigation of the genetic basis of psychiatric disorders first requires us to examine to what extent genes and environment contribute to a given disorder or trait. Secondly, we need to know how genes and environmental influences exert their risk effects and finally we have to investigate the genetic basis of disorders at a molecular level. Traditional methods in psychiatric genetics research include family, twin, and adoption studies. Family studies enable us to examine to what extent a disorder or trait aggregates in families. Familiality of a disorder can of course by explained by shared environmental influences as well as by shared genes. Twin and adoption studies allow us to disentangle the effects of genes and shared environment. The statistical methods used in quantitative genetics may seem complex, the principles are straightforward. Here the authors consider the methods of analyses that are most commonly used for examining the contribution of genetic and environmental factors, to psychiatric disorders and traits. Finally, they discuss gene mapping, and molecular genetic studies investigating gene–environment interplay and intermediate phenotypes.
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Glahn, David C., Laura Almasy y John Blangero. "Endophenotypes". En Psychiatric Genetics, 103–6. Oxford University Press, 2018. http://dx.doi.org/10.1093/med/9780190221973.003.0007.
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Endophenotypes are traits that, while genetically related to an illness, are not used for diagnoses (e.g., a symptom). It is unlikely that specific genes directly code for any of our current psychiatric diagnoses. Rather, genes influence neurobiological processes that either increase or decrease risk for mental illness. One use of an endophenotype is to help characterize a genetic locus or gene previously identified as conferring risk for a particular illness. In this context, endophenotypes help to bridge the gap between a behavioral syndrome and molecular genetic variation. Alternately, endophenotypes can be used for novel locus or gene discovery, particularly when used in multivariate analyses. In this chapter, we define endophenotypes and describe different ways they have been applied to aid our understanding of the genetic architecture of psychiatric disorders.
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Eyries, Mélanie, Barbara Girerd, David Montani, David-Alexandre Tregouët, Marc Humbert y Florent Soubrier. "Pulmonary hypertension genes as major diagnostic tools". En ESC CardioMed, editado por Marc Humbert, 2490–93. Oxford University Press, 2018. http://dx.doi.org/10.1093/med/9780198784906.003.0577.
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A few genes have been shown to be major predisposing factors for pulmonary hypertension and are responsible for heritable forms of the disease. However, for nearly all genes described, not all mutation carriers develop the disease (autosomal transmission with incomplete penetrance) explaining the presence of genetic mutations in apparently sporadic cases. Beside mutations in major genes (BMPR2 for pulmonary arterial hypertension and EIF2AK4 for recessive heritable pulmonary veno-occlusive disease), other genes have been involved in a very limited number of cases (KCNK3, CAV1, and Smad8). Gene mutations are also been found as part of syndromic diseases (ACVRL1 mutations in hereditary haemorrhagic telangiectasia and TBX4 in small patella syndrome).
Actas de conferencias sobre el tema "Il gene MEF"
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Goveia, Rebeca Mota, Paula Francinete Faustino Silva, Thais Bomfim Teixeira, Isabela Gasparini Arraes, Ruffo Freitas-Júnior y Elisângela Paula Silveira Lacerda. "ANALYSIS OF PATHOGENIC AND UNCERTAIN SIGNIFICANCE VARIANTS IN NINE GENES OF THE BRCA1-MEDIATED HOMOLOGOUS RECOMBINATION PATHWAY IN PATIENTS WITH SUSPECTED HEREDITARY BREAST AND OVARIAN CANCER SYNDROME IN CENTRAL BRAZIL." En Scientifc papers of XXIII Brazilian Breast Congress - 2021. Mastology, 2021. http://dx.doi.org/10.29289/259453942021v31s1038.
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Introduction: Breast cancer is the most frequent type of cancer in the world and the biggest cause of female deaths. About 10%–15% of cases are due to hereditary factors. The profile of genetic variants is still scarcely known among the Brazilian population and there are no published data for the central region of the country. Objectives: This study aimed to analyze the profile of pathogenic variants (PV) and of the ones of uncertain significance (VUS) for the RAD50, RAD51C, RAD51D, ATM, PALB2, BRIP1, BARD1 and CHEK2 genes in this population. Methods: 113 patients diagnosed with breast or ovarian cancer who met the National Comprehensive Cancer Networking criteria for hereditary breast and ovarian cancer syndrome were selected. The genes had all regions sequenced using NGS (New Generation Sequencing) and the raw data were evaluated using the Sophia DDM and IonReporter softwares. Results: A total of 3.53% of patients had PV in the PALB2 (c.2257C>T), BARD1 (c.176_177delAG), RAD50 (c.2165dupA) or ATM (c.7913G>A) genes. Patients with pathogenic variants in ATM and PALB2 genes were diagnosed before the age of 40. Patients with pathogenic variants in the BARD1 and RAD50 genes had triple negative breast cancer before the age of 60. The patient with a pathogenic variant in the RAD50 gene also developed ovarian cancer. It was observed that 24.77% of the patients had some VUS, 35.29% of which were in the ATM gene, and a new VUS in the CHEK2 gene (c.1151T>C), related to male breast cancer. Conclusions: These findings contribute to a better understanding of the phenotype of patients with pathogenic variants related to breast cancer in non-BRCA genes. In addition, it reveals a new pathogenic variant in the CHEK2 gene, not described in the literature, related to a case of male breast cancer.
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Campos, Ligia Ribeiro de, Maria Luiza Lyczacovski Riesemberg, Maria Victória Ferreira Piccoli y Milene Krefer Machado. "MECANISMOS GÊNICOS RELACIONADOS ÀS ETAPAS DO PROCESSO EMBRIONÁRIO DE DIFERENCIAÇÃO SEXUAL". En I Congresso On-line Nacional de Histologia e Embriologia Humana. Revista Multidisciplinar em Saúde, 2022. http://dx.doi.org/10.51161/rems/3218.
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Introdução: A diferenciação sexual ocorre em torno da sétima semana após a fertilização, que estabelece o sexo cromossômico. Esse processo é mediado por genes, os quais, expressos ou não, geram uma cascata de fatores e hormônios que diferenciam morfológica e funcionalmente estruturas primitivas do embrião resultando na manifestação sexual fenotípica. Objetivos: Destacar a implicação dos genes SRY, DAX 1 e SOX9, bem como fatores e hormônios decorrentes da expressão ou não desses no fenômeno de diferenciação sexual. Assim como diferenças entre esses processos conforme o sexo cromossômico. Metodologia: Este estudo consistiu em uma revisão literária de artigos escritos em inglês e português publicados nas bases de dados “Pubmed”, “Scielo”, no período entre 2000 e 2021. Resultados: Com base na análise literária, destaca-se o processo de diferenciação gonadal no período embrionário, através das características e importância de cada gene. A princípio, o fator determinante testicular (TDF) é responsável por ativar o gene SOX9, que tem sua expressão evidenciada nas células de Sertoli e ausente no tecido ovariano. Tal fator - codificado pelo gene SRY e expresso pelas células somáticas dos cordões sexuais masculinos - auxilia na diferenciação primeiramente de células de Sertoli e secundariamente em células de Leydig, que em conjunto formam os testículos. Ademais, os ductos paramesonéfricos regridem devido à secreção do hormônio antimulleriano (MIF) e os mesonéfricos mantêm-se, em seguida com o auxílio da di-hidrotestosterona, diferenciam-se em genitália externa masculina. Enquanto em indivíduos do sexo feminino, que não expressam o gene SRY e o TDF mas sim o DAX-1, há a inibição da formação testicular. Bem como, os fatores Wnt4 e Rspo1 estimulam a diferenciação de células foliculares em ovogônias e, por fim, a formação dos ovários. Ocorre também a não regressão dos ductos paramesonéfricos devido à ausência de MIF, permitindo o desenvolvimento das estruturas da genitália interna feminina. Conclusão: Evidencia-se, então, o destaque da atuação gênica bem como o desencadeamento de fatores e hormônios relacionados a ela quanto o fenômeno embriogênico da diferenciação sexual.
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Fabri, Júlia Campos, Maria Julia Filgueiras Granato, Maria Clara Lopes Rezende, Maria Luiza Franco de Oliveira y Leandro de Souza Cruz. "The impact of genetic polymorphism in pain mechanisms". En XIII Congresso Paulista de Neurologia. Zeppelini Editorial e Comunicação, 2021. http://dx.doi.org/10.5327/1516-3180.708.
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Background:Variations in genes codifying target structures in the nociceptive pathway can result in pain attenuation or increase.Objective:Investigate the genetic polymorphism influence in the individual pain threshold. Methods: Search on PubMed with the terms “genetic”, “pain” and its synonyms published in the last 10 years. Results:The subjective and individual mechanisms of pain aren’t completely understood, but genetic susceptibility is one of the hypothesis to explain these differences.The KCNK18 gene influences the synaptic transmission by producing potassium channel protein that equalizes resting membrane potential, calcineurin activated and inhibited by arachidonic acid. This gene was found more frequently in migraine individuals. The COMT gene increase the sensibility to pain by met-enkephalins reduction and/or catecholamine elevation. Its activity’s reduced in fibromyalgia patients. However, the OPRM1 gene, an opioid receptor, was found in individuals with a higher pain threshold.Furthermore, studies with human cell culture shows the analgesic role of the gene A118G, by its greater binding affinity for β-endorphin.It is associated with more effective endorphinergic endogenous pain inhibition. Conclusion:Researches indicates a striking participation of genetic polymorphism in pain mechanisms. The knowledge about genetic variables on pain perception can contribute to the development of individualized analgesic protocols and therapeutic strategies, accordantly to the patient genetic profile. This evolution becomes fundamental in a population that tend to the indiscriminate use of analgesics.
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Иргашев, Дильмурад Саатович. "THE PREVALENCE OF THE ILE462VAL POLYMORPHISM OF THE CYP1A1 GENE AMONG MEN WITH INFERTILITY IN THE UZBEK POPULATION". En Psychology, Sports science and Medicine (Психология. Спорт. Здравоохранение): сборник статей международной научной конференции (Санкт-Петербург, Октябрь 2022). Crossref, 2022. http://dx.doi.org/10.37539/221030.2022.50.28.006.
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Существенным фактором, формирования мужского бесплодия с позиций доказательной медицины, являются нарушения в системе генов детоксикации ксенобиотиков. Проведен анализ роли полиморфизма Ile462Val гена CYP1A1 в формировании мужского бесплодия. Полученные результаты исследования косвенно указывают на дисрегуляторное влияние неблагоприятного аллельного варианта данного полиморфизма на экспрессию цитохрома CYP1A1. An essential factor in the formation of male infertility from the standpoint of evidence-based medicine are disorders in the system of xenobiotic detoxification genes. The role of the Ile462Val polymorphism of the CYP1A1 gene in the formation of male infertility was analyzed. The obtained results of the study indirectly indicate the dysregulatory effect of the unfavorable allelic variant of this polymorphism on the expression of cytochrome CYP1A1.
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Ayoub, Dibe Balardini. "BASES ORIGINÁRIAS DAS NEOPLASIAS HEMATOLÓGICAS". En II Congresso Brasileiro de Hematologia Clínico-laboratorial On-line. Revista Multidisciplinar em Saúde, 2022. http://dx.doi.org/10.51161/hematoclil/37.
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Introdução: A compreensão das bases originárias de neoplasias hematológicas é imprescindível para o combate a leucemias, linfomas e síndromes mielodisplásicas. Nesse viés, percebe-se a importância do estudo acerca dessas bases, isto é, os genes envolvidos, a fim de possivelmente identificá-los e impedir que gerem a proliferação de neoplasias desse caráter. Objetivos: O presente estudo tem por objetivo principal apresentar bases teóricas, a nível molecular, para o entendimento daquilo que se configura como uma neoplasia hematológica. Tornando assim possível a consolidação do conhecimento acerca desses tipos de câncer. Material e Métodos: Consonante ao objetivo principal, realizou-se uma revisão bibliográfica atualizada, a fim de elencar os elementos chaves que são os potenciais originários das neoplasias. Para tal, foi feito um levantamento comparativo dos genes que mais influenciam na ruptura da homeostase sendo eles os principais desencadeadores de neoplasias. Resultados: Com base na revisão bibliográfica evidenciou-se a importância de certos fatores desencadeadores de neoplasias de caráter hematológico, sendo eles alterações em partes do processo de oncogênese que passam a gerar falhas no sistema de homeostase. Dentre essas alterações estão o comprometimento do metabolismo energético relacionado às mutações do IDH1/2; a suscetibilidade à morte celular programada em consequências às mutações de inativação do gene supressor P53 ou do AKT; a instabilidade do genoma e mutações relacionadas às modificações nos genes FANC ; a influência da angiogênese por conta da superexpressão do VEGFA (gene de crescimento vascular endotelial); habilidade de invadir e realizar metástase por conta da deleção de TIMP3 uma inibidora tecidual de metaloproteinase ou ampliação dos potenciais proto-oncogenes MET ou HGF; indução à resposta inflamatória por meio da desregulação do fator nuclear kappa B; a resistência a sinais que inibem a proliferação mutagênica por conta do aumento na ação de genes CDKA CDK6, CCND2 ou na deleção do CDKN2, bem como desvio do sistema imune e multiplicação indefinida. Conclusão: Conforme o exposto, pode-se concluir que as alterações durante a oncogênese são cruciais para o desenvolvimento de neoplasias de caráter hematológicas, ora pela inativação em determinados genes, ora pela superexpressão de outros que se expressam no sangue ou em tecidos dele formadores.
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Manukyan, I. R. y N. N. Dogusova. "Resistance of winter wheat cultivars to leaf rust in conditions of the Central Caucasus". En General question of world science. Наука России, 2021. http://dx.doi.org/10.18411/gq-31-03-2021-14.
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The main problem of wheat immunity to leaf rust is the loss of efficiency of most Lrgenes. The decrease in efficiency is associated with microevolutionary processes within the population and the emergence of new virulent phytopathogen races that can overcome previously efficient resistance genes. The article presents the results of the phytopathological test and marker analysis of the selected material of winter wheat for resistance to the leaf rust pathogen (Puccinia recondita Rob.ex Desm f. sp. tritici.). The object of the research was 20 cultivar samples of various ecological and geographical origins. DNA was isolated from the leaves of 10-day-old wheat germs. Molecular markers were used for the following genes: Lr9 (SCS5), Lr10 (Fi.2245/Lr10-6/r2), Lr19/Sr25 (SCS265), Lr20/Sr15 (STS638), Lr24/Sr24 (Sr24#12), Lr34/Sr57 (csLV34), Lr37/Sr38/Yr17/Pch2/Cre5 (Ventriup/LN2), Lr41 (GDM35), Lr47 (PS10). Using molecular markers, the studied wheat varieties did not reveal the highly and partially effective genes Lr9, Lr19/Sr25, Lr24/Sr24, Lr41, and Lr47 in Russia, and the ineffective gene Lr20/Sr1. As a result of molecular screening, it was found that the List 25 variety had Lr37 genes; the Mif variety had Lr10 genes; the Eltan variety had Lr10 genes; the Markola variety had Lr34 genes; the Malvina variety had Lr26 genes; the Tvorets variety had Lr10 genes; the DB 1/05 variety had Lr10 genes; the Evklid variety had Lr10 genes; the Sumai aut variety had Lr34 genes; the Lebidka odes'ka variety had Lr34 genes; the Solara variety – Lr34; the Zhiva variety – Lr10, Lr34. When comparing the results of marker analysis with field resistance to leaf rust, the resistant type of reaction to infection (R) was shown by the cultivars: Battum, Eltan, Evklid, Areal, and Solara; the susceptible type of reaction (S) was noted in the cultivars Markola and Mallyska; the medium susceptible type of reaction (MS) – in the cultivars Lebidka odes'ka and Tvorets.
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Azmi, Muhammad Bilal. "In Silico Basis to Understand the Molecular Interaction of Human NNATGene With Therapeutic Compounds of Anorexia Nervosa". En INTERNATIONAL CONFERENCE ON BIOLOGICAL RESEARCH AND APPLIED SCIENCE. Jinnah University for Women, Karachi,Pakistan, 2022. http://dx.doi.org/10.37962/ibras/2022/1-2.
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Introduction: Anorexia nervosa (AN)– a perplexing heritable, psychiatric eating disorder condition characterized by low body weight. The prevalence of AN is found to be high in younger age adults with a raised mortality rate. Genetic studies have been insufficient in identifying the role of specific genes that predispose an individual to AN. Objectives: The objective was to explore the role of NNAT (neuronatin) gene variants and its structure based molecular interactions with therapeutic compounds of AN. To investigate the role of structural missense pathogenic variants (SNPs: single nucleotide polymorphism) or change in the expression of NNAT with possibility of AN. Methodology: NNAT gene protein coding sequence, SNPs were extracted and validated from public databases. Gene to gene interactions, protein localization and human tissue-specific expression analysis of NNAT gene showed highest tissue-specific expression in the brain. Estimates of functional impact of SNPs using transcript sequence and machine learning based approaches (in silico algorithms) were computed to investigate the pathogenicity and protein stability of NNAT variants. Sequence alignment, ab initio 3D structure-modeling of wild-type, validation and recognition of binding cavities of NNAT through in silico web based tools were performed. Alternate model prediction for NNAT variants through residue specific mutation approach and structural validation were also done through Chimera tool. The 3D compounds involved in the management of AN were extracted from the Drug Bank database, afterwards energy minimization and rule of drug-likeness were performed. The eligible 3D compounds were docked with identified variants, to evaluate the drugs binding molecular mechanics. Results & Conclusion: Overall, 10 NNAT missense variants were extracted on the basis of minor allele frequency (MAF < 0.001) and other consequence types. Further three variants were selected among ten according to the transcript sequence, which includesrs542858994 (F26L), rs539681368 (C30Y) and rs542858994 (F53L). Structures for these variants’ protein were generated, validated and docked with AN drugs. The functional impact analyses of selected missense SNPs of NNAT showed high risk pathogenicity and can cause changes in the physical and chemical properties of amino acids, thus affecting the function of protein. The computation of binding energies of variants of NNAT with AN compounds strengthen the hypothesis that these variants strongly interact with the AN drugs, hence reducing the level of free NNAT as well as target drugs, for neuronal functioning. Therefore, constitutionally reduced level of NNAT and binding of NNAT variants with AN drugs may serve as the basis to increases the susceptibility towards AN.
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Banjin, Maja, Amina Jalovčić y Velda Smajlbegović. "CILJANA TERAPIJA I METASTATSKI MELANOM". En Okrugli sto s međunarodnim učešćem "Melanom". Akademija nauka i umjetnosti Bosne i Hercegovine, 2018. http://dx.doi.org/10.5644/pi2019.180.02.
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Melanom je globalni zdravstveni problem s kontinuiranim porastom u incidence. Rezultati tretmana metastatskog melanoma su, do skorašnjih napredovanja u terapijama, bili slabi, s medijanom ukupnog preživljavanja (OS) od 7,5 mjeseci i petogodišnjom stopom preživljavanja 6%. U kliničkim istraživanjima za metastatski melanom, selektivni inhibitori BRAF gena, vemurafenib i dabrafenib, pokazali su značajnu antitumorsku aktivnost i poboljšanje u OS i PFS kada se porede s dakarbazinom. Međutim, skoro će svaki pacijent tretiran BRAF inhibitorima imati progresiju bolesti, a tumori pokazuju reaktivacije MAPK puta u vrijeme pojave rezistencije. Specifična BRAF inhibicija vodi ka paradoksalnoj aktivaciji ćelija s RAS divljim “wild” genom uzvodno u MAPK putu i iz tih razloga vodi rezistenciji na terapiju, ćelijskoj proliferaciji i povećanoj stopi RAS kožnog toksiciteta. Pretklinički podaci sugerisali su da inhibitori MEK gena u MAPK putu mogu da zaustave rast i isprovociraju ćelijsku smrt kod nekih BRAF pozitivnih melanomskih tumora. Selektivni inhibitori MEK1 i MEK2 su cobimetinib i trametinib. Kombinovanjem BRAF+MEK inhibicije postiže se produženje terapijskog odgovora, odgađanje rezistencija i smanjuje pojava novih kutanih SCC/KA udruženih s BRAF inhibicijom. Kombinacija dabrafenib+ trametinib i vemurafenib+cobimetinib odobrena je za pacijente s neresktabilnim ili metastatskim melanomom s tumorima koji imaju mutaciju na BRAF genu. Klinička vrijednost intermitentne terapije za sada nije definisana. Podaci iz kliničkih istraživanja sugerišu da selekcionirani pacijenti mogu imati benefit od terapije uprkos razvijanju novih metastaza. Uvođenje ovih terapija u adjuvantno područje može dodatno poboljšati ishod i liječenje ove bolesti.
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Ndiaye, I., M. Chaves y J. L. Gouze. "Study and parameter identification of a model coupling cell signaling and gene expression". En Automation (MED 2008). IEEE, 2008. http://dx.doi.org/10.1109/med.2008.4602118.
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Spieker, Michael A., Linda J. Hayes, Eugene H. Wissler y David P. Colvin. "Analysis of Gender Based Thermal Regulation". En ASME 1999 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 1999. http://dx.doi.org/10.1115/imece1999-0574.
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Abstract Significant qualitative and quantitative data from the literature suggests that men and women differ in their response to extreme thermal environments. It is apparent that women sweat less (Morimoto et al., 1967; Wyndham et al., 1965), and have a thicker subcutaneous fat layer (Wells, 1991) relative to men. Men, on the other hand have higher resting and working metabolic rates relative to women, which tend to increase their core body temperatures at a faster rate. A whole body thermal regulation model (Wissler, 1985) designed by Gene Wissler is used to analyze the gender based thermal responses of men and women subjected to medium-high work levels in several thermal environments. This study has important application in estimating how gender differences affect the potential work performance of men and women in extreme thermal environments.
Informes sobre el tema "Il gene MEF"
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Ohad, Nir y Robert Fischer. Control of Fertilization-Independent Development by the FIE1 Gene. United States Department of Agriculture, agosto de 2000. http://dx.doi.org/10.32747/2000.7575290.bard.
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A fundamental problem in biology is to understand how fertilization initiates reproductive development. During plant reproduction, one sperm cell fuses with the egg to form an embryo, whereas a second sperm cell fuses with the adjacent central cell nucleus to form the endosperm tissue that supports embryo and/or seedling development. To understand the mechanisms that initiate reproduction, we have isolated mutants of Arabidopsis that allow for replication of the central cell and subsequent endosperm development without fertilization. In this project we have cloned the MEA gene and showed that it encode a SET- domain polycomb protein. Such proteins are known to form chromatin-protein complexes that repress homeotic gene transcription and influence cell proliferation from Drosophylla to mammals. We propose a model whereby MEA and an additional polycomb protein we have cloned, FIE , function to suppress a critical aspect of early plant reproduction and endosperm development, until fertilization occurs. Using a molecular approach we were able to determine that FIE and MEA interact physically, suggesting that these proteins have been conserved also during the evolution of flowering plants. The analysis of MEA expression pattern revealed that it is an imprinted gene that displays parent-of- origin-dependent monoallelic expression specifically in the endosperm tissue. Silencing of the paternal MEA allele in the endosperm and the phenotype of mutant mea seeds support the parental conflict theory for the evolution of imprinting in plants and mammals. These results contribute new information on the initiation of endosperm development and provide a unique entry point to study asexual reproduction and apomixis which is expected to improve crop production.
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Ohad, Nir y Robert Fischer. Regulation of Fertilization-Independent Endosperm Development by Polycomb Proteins. United States Department of Agriculture, enero de 2004. http://dx.doi.org/10.32747/2004.7695869.bard.
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Arabidopsis mutants that we have isolated, encode for fertilization-independent endosperm (fie), fertilization-independent seed2 (fis2) and medea (mea) genes, act in the female gametophyte and allow endosperm to develop without fertilization when mutated. We cloned the FIE and MEA genes and showed that they encode WD and SET domain polycomb (Pc G) proteins, respectively. Homologous proteins of FIE and MEA in other organisms are known to regulate gene transcription by modulating chromatin structure. Based on our results, we proposed a model whereby both FIE and MEA interact to suppress transcription of regulatory genes. These genes are transcribed only at proper developmental stages, as in the central cell of the female gametophyte after fertilization, thus activating endosperm development. To test our model, the following questions were addressed: What is the Composition and Function of the Polycomb Complex? Molecular, biochemical, genetic and genomic approaches were offered to identify members of the complex, analyze their interactions, and understand their function. What is the Temporal and Spatial Pattern of Polycomb Proteins Accumulation? The use of transgenic plants expressing tagged FIE and MEA polypeptides as well as specific antibodies were proposed to localize the endogenous polycomb complex. How is Polycomb Protein Activity Controlled? To understand the molecular mechanism controlling the accumulation of FIE protein, transgenic plants as well as molecular approaches were proposed to determine whether FIE is regulated at the translational or posttranslational levels. The objectives of our research program have been accomplished and the results obtained exceeded our expectation. Our results reveal that fie and mea mutations cause parent-of-origin effects on seed development by distinct mechanisms (Publication 1). Moreover our data show that FIE has additional functions besides controlling the development of the female gametophyte. Using transgenic lines in which FIE was not expressed or the protein level was reduced during different developmental stages enabled us for the first time to explore FIE function during sporophyte development (Publication 2 and 3). Our results are consistent with the hypothesis that FIE, a single copy gene in the Arabidopsis genome, represses multiple developmental pathways (i.e., endosperm, embryogenesis, shot formation and flowering). Furthermore, we identified FIE target genes, including key transcription factors known to promote flowering (AG and LFY) as well as shoot and leaf formation (KNAT1) (Publication 2 and 3), thus demonstrating that in plants, as in mammals and insects, PcG proteins control expression of homeobox genes. Using the Yeast two hybrid system and pull-down assays we demonstrated that FIE protein interact with MEA via the N-terminal region (Publication 1). Moreover, CURLY LEAF protein, an additional member of the SET domain family interacts with FIE as well. The overlapping expression patterns of FIE, with ether MEA or CLF and their common mutant phenotypes, demonstrate the versatility of FIE function. FIE association with different SET domain polycomb proteins, results in differential regulation of gene expression throughout the plant life cycle (Publication 3). In vitro interaction assays we have recently performed demonstrated that FIE interacts with the cell cycle regulatory component Retinobalsoma protein (pRb) (Publication 4). These results illuminate the potential mechanism by which FIE may restrain embryo sac central cell division, at least partly, through interaction with, and suppression of pRb-regulated genes. The results of this program generated new information about the initiation of reproductive development and expanded our understanding of how PcG proteins regulate developmental programs along the plant life cycle. The tools and information obtained in this program will lead to novel strategies which will allow to mange crop plants and to increase crop production.
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Ohad, Nir y Robert Fischer. Regulation of plant development by polycomb group proteins. United States Department of Agriculture, enero de 2008. http://dx.doi.org/10.32747/2008.7695858.bard.
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Our genetic and molecular studies have indicated that FIE a WD-repeat Polycomb group (PcG) protein takes part in multi-component protein complexes. We have shown that FIE PcG protein represses inappropriate programs of development during the reproductive and vegetative phases of the Arabidopsis life cycle. Moreover, we have shown that FIE represses the expression of key regulatory genes that promote flowering (AG and LFY), embryogenesis (LEC1), and shoot formation (KNAT1). These results suggest that the FIE PcG protein participates in the formation of distinct PcG complexes that repress inappropriate gene expression at different stages of plant development. PcG complexes modulate chromatin compactness by modifying histones and thereby regulate gene expression and imprinting. The main goals of our original project were to elucidate the biological functions of PcG proteins, and to understand the molecular mechanisms used by FIE PcG complexes to repress the expression of its gene targets. Our results show that the PcG complex acts within the central cell of the female gametophyte to maintain silencing of MEA paternal allele. Further more we uncovered a novel example of self-imprinting mechanism by the PgG complex. Based on results obtained in the cures of our research program we extended our proposed goals and elucidated the role of DME in regulating plant gene imprinting. We discovered that in addition to MEA,DME also imprints two other genes, FWA and FIS2. Activation of FWA and FIS2 coincides with a reduction in 5-methylcytosine in their respective promoters. Since endosperm is a terminally differentiated tissue, the methylation status in the FWA and FIS2 promoters does not need to be reestablished in the following generation. We proposed a “One-Way Control” model to highlight differences between plant and animal genomic imprinting. Thus we conclude that DEMETER is a master regulator of plant gene imprinting. Future studies of DME function will elucidate its role in processes and disease where DNA methylation has a key regulatory role both in plants and animals. Such information will provide valuable insight into developing novel strategies to control and improve agricultural traits and overcome particular human diseases.
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Sengupta-Gopalan, Champa, Shmuel Galili y Rachel Amir. Improving Methionine Content in Transgenic Forage Legumes. United States Department of Agriculture, febrero de 2001. http://dx.doi.org/10.32747/2001.7580671.bard.
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Leguminous forage crops are high in proteins but deficient in S- amino acids. It has been shown that both wool quality and milk production can be limited by the post-ruminal supply of sulfur-containing amino acids. Efforts to use conventional plant breeding and cell selection techniques to increase the S-amino acid content of alfalfa have met with little success. With the objective to increase the S-amino acid content of forage legumes, the goal of this project was to co- express the methionine rich zein genes from corn along with a gene for a key enzyme in methionine biosynthesis, aspartate kinase(AK). The zeins are seed storage proteins from corn and are groupec into four distinct classes based on their amino acid sequence homologies. The b-zein (15kd) and the 6zein (10kD and 18kD) have proportionately high levels of methionine (10%, 22% and 28%, respectively). Initial studies from our lab had shown that while the 15kD zein accumulated to high levels in vegetative tissues of transgenic tobacco the l0kD zein did not. However, co-expression of the 10kD zein with the 15kD zein genes in tobacco showed stabilization of the 10kD zein and the co-localization of the 10kD and 15kD zein proteins in unique ER derived protein bodies. AK is the key enzyme for producing carbon skeletons for all amino acids of the aspartate family including methionine. It is, however, regulated by end-product feedback inhibition. The specific objectives of this proposal were: i. to co-express the 15kD zein with the 10/18kD zein genes in alfalfa in order to enhance the level of accumulation of the 10/18kD zein; ii. to increase methionine pools by expressing a feedback insensitive AK gene in transformants co-expressing the 15kD and 10/18kD zein genes. The Israeli partners were successful in expressing the AK gene in alfalfa which resulted in an increase in free and bound threonine but not in methionine (Galili et al., 2000). Since our target was to increase methionine pools, we changed our second objective to replace the AK gene with the gene for cystathionine gamma synthase (CGS) in the co-expression studies. The first methionine specific reaction is catalyzed by CGS. An additional objective was to develop a transformation system for Berseem clover, and to introduce the appropriate gene constructs into it with the goal of improving their methionine content. Genes for the 15kD zein along with the genes for either the 10kD or 18kD zein have been introduced into the same alfalfa plant both by sexual crosses and by re-transformation. Analysis of these zein co-expressors have shown that both the IOkD and 18kD zein levels go up 5 to 10 fold when co-expressed with the 15kD zein (Bagga et al., MS in preparation). Incubation of the leaves of transgenic alfalfa co-expressing the 15kD and 10kD zein genes, in the rumen of cows have shown that the zein proteins are stable in the rumen. To increase the level of zein accumulation in transgenic alfalfa different promoters have been used to drive the zein genes in alfalfa and we have concluded that the CaMV 35S promoter is superior to the other strong leaf -specific promoters. By feeding callus tissue of alfalfa plants co-expressing the 15kD and 10kD zein genes with methionine and its precursors, we have shown that the zein levels could be significantly enhanced by increasing the methionine pools. We have now introduced the CGS gene (from Arabidopsis; kindly provided to us by Dr. Leustek), into the 15kD zein transformants and experiments are in progress to check if the expression of the CGS gene indeed increases the level of zein accumulation in alfalfa. We were not successful in developing a transformation protocol for Berseem clover.
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Petz, Lawrence N. Expression of the Estrogen-Regulated pS2 Gene in MCF-7 Human Breast Cancer Cells. Fort Belvoir, VA: Defense Technical Information Center, agosto de 2001. http://dx.doi.org/10.21236/ada398062.
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Petz, Lawrence N. Expression of the Estrogen-Regulated pS2 Gene in MCF-7 Human Breast Cancer Cells. Fort Belvoir, VA: Defense Technical Information Center, agosto de 1998. http://dx.doi.org/10.21236/ada360028.
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Petz, Lawrenec N. Expression of the Estrogen-Regulated pS2 Gene in MCF-7 Human Breast Cancer Cells. Fort Belvoir, VA: Defense Technical Information Center, agosto de 2000. http://dx.doi.org/10.21236/ada392813.
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Melkoumian, Zaroui. Regulation of C-myc Gene Expression by Potassium Channel Blocker Quindine in MCF-7 Human Breast Cancer Cell Line. Fort Belvoir, VA: Defense Technical Information Center, julio de 2000. http://dx.doi.org/10.21236/ada384096.
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Amir, Rachel, David J. Oliver, Gad Galili y Jacline V. Shanks. The Role of Cysteine Partitioning into Glutathione and Methionine Synthesis During Normal and Stress Conditions. United States Department of Agriculture, enero de 2013. http://dx.doi.org/10.32747/2013.7699850.bard.
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The objective of this research is to study the nature of the competition for cysteine (Cys), the first organic sulfur-containing compound, between its two main metabolites, glutathione (GSH) and methionine (Met). GSH plays a central role in protecting plants during various stresses, while Met, an essential amino acid, regulates essential processes and metabolites in plant cells through its metabolite S-adenosyl-Met. Our results, which are based on flux analysis and measurements of Met- metabolites, show that the flux towards Met synthesis is high during non-stress conditions, however the flux is significantly reduced under stress conditions, when there is high synthesis of GSH. Under oxidative stress the expression level of the regulatory enzyme of Met synthesis, cystathionine g-synthase (CGS) was reduced. By using three different systems, we have found that that GSH down regulates the expression level of CGS, thus reducing Met synthesis. We have found that this regulation occurs at the post-transcriptional level, and further studies have shown that it occurs at post-translationaly. To reveal how oxidative stress affects the flux towards Met and GSH, flux analysis was performed. We have found that the level of Met is significantly reduced, while the level of glutathione significantly increases during stress. Under stress conditions most of the glutathione is converted from GSH to GSSG (the oxidised form of glutathione). These results suggest that under normal growth conditions, Cys is channelled towards both pathways to support GSH accumulation and the synthesis of growth-essential Met metabolites. However, during oxidative stress, when a high level of GSH is required to protect the plants, the levels of GSH increase while those of CGS are reduced. This reduction leaves more Cys available for GSH synthesis under stress conditions. In addition we have also studied the effects of high GSH level on the transcriptome profile. The analysis revealed that GSH affects the expression level of many major genes coding to enzymes or proteins associated with photosynthesis, starch degradation, hormone metabolism (especially genes associated with jasmonate), biotic stress (especially genes associated with PR-proteins), cytochrome P450 genes, regulation of transcription and signaling (especially genes associated with receptor kinases and calcium). These results suggest that indeed GSH levels affect different pathways and metabolites in plants.
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Bova, G. S. Pilot Comparison of Stromal Gene Expression Among Normal Prostate Tissues and Primary Prostate Cancer Tissues in White and Black Men. Fort Belvoir, VA: Defense Technical Information Center, septiembre de 2005. http://dx.doi.org/10.21236/ada456139.
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