Bibliografie tematiche / Chromosome inversions

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Letteratura scientifica selezionata sul tema "Chromosome inversions"

Autore: Grafiati

Pubblicato: 4 giugno 2021

Ultima modifica: 18 febbraio 2022

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Articoli di riviste sul tema "Chromosome inversions"

Kaiser, P. E., J. A. Seawright e B. K. Birky. "Chromosome polymorphism in natural populations of Anopheles quadrimaculatus Say species A and B". Genome 30, n. 2 (1 aprile 1988): 138–46. http://dx.doi.org/10.1139/g88-024.

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Ovarian polytene chromosomes from eight populations of Anopheles quadrimaculatus in the southeastern United States were observed for chromosomal polymorphisms. Two sibling species, species A and B, each with intraspecific inversions, were distinguished. Species A correlates with the previously published standard maps for salivary gland and ovarian nurse-cell polytene chromosomes. Species A was found at all eight collection sites, and five of these populations also contained species B. Three inversions on the right arm of chromosome 3 were observed in species A. Species B contained a fixed inversion on the X chromosome, one fixed and one floating inversion on the left arm of chromosome 2, and one fixed and one floating inversion on the right arm of chromosome 3. The fixed inversion on the X chromosome makes this the best diagnostic chromosome for distinguishing species A and B. An unusual dimorphism in the left arm of chromosome 3, found in both species A and B, contained two inversions. The heterokaryotypes, as well as two distinct homokaryotypes, were seen in all of the field populations. Intraspecific clinal variations in the frequencies of the species A inversions were noted. The Florida populations were practically devoid of inversions, the Georgia and Alabama populations contained some inversions, and the Arkansas population was mostly homozygous for two of the inversions. The phylogenetic relationships of species A and B to the Maculipennis complex (Nearctic) are discussed.Key words: Anopheles, inversion, populations, chromosome polymorphism, phylogenetics.

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Ruiz, Alfredo, José María Ranz, Mario Cáceres e Carmen Segarra. "Chromosomal evolution and comparative gene mapping in the Drosophila repleta species group". Brazilian Journal of Genetics 20, n. 4 (dicembre 1997): 553–65. http://dx.doi.org/10.1590/s0100-84551997000400003.

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A review of our recent work on the cromosomal evolution of the Drosophila repleta species group is presented. Most studies have focused on the buzzatii species complex, a monophyletic set of 12 species which inhabit the deserts of South America and the West Indies. A statistical analysis of the length and breakpoint distribution of the 86 paracentric inversions observed in this complex has shown that inversion length is a selected trait. Rare inversions are usually small while evolutionary successful inversions, fixed and polymorphic, are predominantly of medium size. There is also a negative correlation between length and number of inversions per species. Finally, the distribution of inversion breakpoints along chromosome 2 is non-random, with chromosomal regions which accumulate up to 8 breakpoints (putative "hot spots"). Comparative gene mapping has also been used to investigate the molecular organization and evolution of chromosomes. Using in situ hybridization, 26 genes have been precisely located on the salivary gland chromosomes of D. repleta and D. buzzatii; another nine have been tentatively identified. The results are fully consistent with the currently accepted chromosomal homologies between D. repleta and D. melanogaster, and no evidence for reciprocal translocations or pericentric inversions has been found. The comparison of the gene map of D. repleta chromosome 2 with that of the homologous chromosome 3R of D. melanogaster shows an extensive reorganization via paracentric inversions and allows to estimate an evolution rate of ~1 inversion fixed per million years for this chromosome

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Fuller, Zachary L., Spencer A. Koury, Christopher J. Leonard, Randee E. Young, Kobe Ikegami, Jonathan Westlake, Stephen Richards, Stephen W. Schaeffer e Nitin Phadnis. "Extensive Recombination Suppression and Epistatic Selection Causes Chromosome-Wide Differentiation of a Selfish Sex Chromosome in Drosophila pseudoobscura". Genetics 216, n. 1 (30 luglio 2020): 205–26. http://dx.doi.org/10.1534/genetics.120.303460.

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Sex-Ratio (SR) chromosomes are selfish X-chromosomes that distort Mendelian segregation and are commonly associated with inversions. These chromosomal rearrangements suppress recombination with Standard (ST) X-chromosomes and are hypothesized to maintain multiple alleles important for distortion in a single large haplotype. Here, we conduct a multifaceted study of the multiply inverted Drosophila pseudoobscura SR chromosome to understand the evolutionary history, genetic architecture, and present-day dynamics that shape this enigmatic selfish chromosome. The D. pseudoobscura SR chromosome has three nonoverlapping inversions of the right arm of the metacentric X-chromosome: basal, medial, and terminal. We find that 23 of 29 Mb of the D. pseudoobscuraX-chromosome right arm is highly differentiated between the Standard and SR arrangements, including a 6.6 Mb collinear region between the medial and terminal inversions. Although crossing-over is heavily suppressed on this chromosome arm, we discover it is not completely eliminated, with measured rates indicating recombination suppression alone cannot explain patterns of differentiation or the near-perfect association of the three SR chromosome inversions in nature. We then demonstrate the ancient basal and medial inversions of the SR chromosome contain genes sufficient to cause weak distortion. In contrast, the younger terminal inversion cannot distort by itself, but contains at least one modifier gene necessary for full manifestation of strong sex chromosome distortion. By parameterizing population genetic models for chromosome-wide linkage disequilibrium with our experimental results, we infer that strong selection acts to maintain the near-perfect association of SR chromosome inversions in present-day populations. Based on comparative genomic analyses, direct recombination experiments, segregation distortion assays, and population genetic modeling, we conclude the combined action of suppressed recombination and strong, ongoing, epistatic selection shape the D. pseudoobscura SR arrangement into a highly differentiated chromosome.

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Ramírez, Corália CL, e Eliana MB Dessen. "Chromosomal evidence for sibling species of the malaria vector Anopheles cruzii". Genome 43, n. 1 (1 febbraio 2000): 143–51. http://dx.doi.org/10.1139/g99-103.

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An analysis of the ovarian polytene chromosomes of Anopheles cruzii from three localities in Southeast Brazil revealed the existence of two genetic entities within this morphologically uniform taxon. These cryptic species differed in the banding patterns of the X chromosome and 3L arm. A pattern of bands that cannot be explained by the fixation of any of the known inversions in chromosome X was revealed and named chromosomal form B to distinguish it from the standard pattern of this X chromosome, form A. Each chromosomal form is characterized by a different set of inversions. The lack of heterozygotes (A/B) for these X chromosome forms in populations where both forms coexist is evidence of absence or limited gene flow between the two groups. Key words: Anopheles cruzii, inversion polymorphism, sibling species.

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Eggleston, William B., Nac R. Rim e Johng K. Lim. "Molecular Characterization of hobo-Mediated Inversions in Drosophila melanogaster". Genetics 144, n. 2 (1 ottobre 1996): 647–56. http://dx.doi.org/10.1093/genetics/144.2.647.

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Abstract The structure of chromosomal inversions mediated by hobo transposable elements in the Uc-1 X chromosome was investigated using cytogenetic and molecular methods. Uc-1 contains a phenotypically silent hobo element inserted in an intron of the Notch locus. Cytological screening identified six independent Notch mutations resulting from chromosomal inversions with one breakpoint at cytological position 3C7, the location of Notch. In situ hybridization to salivary gland polytene chromosomes determined that both ends of each inversion contained hobo and Notch sequences. Southern blot analyses showed that both breakpoints in each inversion had hobo-Notch junction fragments indistinguishable in structure from those present in the Uc-1 X chromosome prior to the rearrangements. Polymerase chain reaction amplification of the 12 hobo-Notch junction fragments in the six inversions, followed by DNA sequence analysis, determined that each was identical to one of the two hobo-Notch junctions present in Uc-1. These results are consistent with a model in which hobo-mediated inversions result from homologous pairing and recombination between a pair of hobo elements in reverse orientation.

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Mahan, M. J., e J. R. Roth. "Ability of a bacterial chromosome segment to invert is dictated by included material rather than flanking sequence." Genetics 129, n. 4 (1 dicembre 1991): 1021–32. http://dx.doi.org/10.1093/genetics/129.4.1021.

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Abstract Homologous recombination between sequences present in inverse order within the same chromosome can result in inversion formation. We have previously shown that inverse order sequences at some sites (permissive) recombine to generate the expected inversion; no inversions are found when the same inverse order sequences flank other (nonpermissive) regions of the chromosome. In hopes of defining how permissive and nonpermissive intervals are determined, we have constructed a strain that carries a large chromosomal inversion. Using this inversion mutant as the parent strain, we have determined the "permissivity" of a series of chromosomal sites for secondary inversions. For the set of intervals tested, permissivity seems to be dictated by the nature of the genetic material present within the chromosomal interval being tested rather than the flanking sequences or orientation of this material in the chromosome. Almost all permissive intervals include the origin or terminus of replication. We suggest that the rules for recovery of inversions reflect mechanistic restrictions on the occurrence of inversions rather than lethal consequences of the completed rearrangement.

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Brianti, Mitsue T., Galina Ananina e Louis B. Klaczko. "Differential occurrence of chromosome inversion polymorphisms among Muller's elements in three species of the tripunctata group of Drosophila, including a species with fast chromosomal evolution". Genome 56, n. 1 (gennaio 2013): 17–26. http://dx.doi.org/10.1139/gen-2012-0074.

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Detailed chromosome maps with reliable homologies among chromosomes of different species are the first step to study the evolution of the genetic architecture in any set of species. Here, we present detailed photo maps of the polytene chromosomes of three closely related species of the tripunctata group (subgenus Drosophila): Drosophila mediopunctata, D. roehrae, and D. unipunctata. We identified Muller's elements in each species, using FISH, establishing reliable chromosome homologies among species and D. melanogaster. The simultaneous analysis of chromosome inversions revealed a distribution pattern for the inversion polymorphisms among Muller's elements in the three species. Element E is the most polymorphic, with many inversions in each species. Element C follows; while the least polymorphic elements are B and D. While interesting, it remains to be determined how general this pattern is among species of the tripunctata group. Despite previous studies showing that D. mediopunctata and D. unipunctata are phylogenetically closer to each other than to D. roehrae, D. unipunctata shows rare karyotypic changes. It has two chromosome fusions: an additional heterochromatic chromosome pair and a pericentric inversion in the X chromosome. This especial conformation suggests a fast chromosomal evolution that deserves further study.

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Michailova, Paraskeva, Julia Ilkova, Pavlo Kovalenko, Artem Dzhulai e Iryna Kozeretska. "Long-term retainment of some chromosomal inversions in a local population of Belgica antarctica Jacobs (Diptera, Chironomidae)". Czech Polar Reports 11, n. 1 (24 agosto 2021): 16–24. http://dx.doi.org/10.5817/cpr2021-1-3.

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Genome of antarctic endemic Belgica antarctica Jacobs has been sequenced. However, no set of inversion diagnostic markers has ever been assigned for the species. Using the classical method of polytene chromosome squash preparation, we found three heterozygous inversions located on the second (two heterozygous inversions) and third chromosomes (one heterozygous inversion) in the Belgica antarctica population of a cape of Wiencke Island, 500 m to SW from Port Lockroy. The chromosome set and chromosome variability did not differ from those described in the literature (Atchley and Davis 1979). Every salivary gland chromosome had its own markers by which it can be determined. However, we did not find a sex-linked inversion on chromosome III and heterozygous inversion on chromosome I, reported in earlier studies. For the first time, we observed a strong heterochromatin band in chromosome III at the telomere of one arm. Our data show not only the stability of the described inversions in the population but also the usefulness of the squash preparation technique in the studies of genetic variability of Belgica antarctica in present time.

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Miesel, L., A. Segall e J. R. Roth. "Construction of chromosomal rearrangements in Salmonella by transduction: inversions of non-permissive segments are not lethal." Genetics 137, n. 4 (1 agosto 1994): 919–32. http://dx.doi.org/10.1093/genetics/137.4.919.

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Abstract Homologous sequences placed in inverse order at particular separated sites in the bacterial chromosome (termed "permissive") can recombine to form an inversion of the intervening chromosome segment. When the same repeated sequences flank other chromosome segments ("non-permissive"), recombination occurs but the expected inversion rearrangement is not found among the products. The failure to recover inversions of non-permissive chromosomal segments could be due to lethal effects of the final rearrangement. Alternatively, local chromosomal features might pose barriers to reciprocal exchanges between sequences at particular sites and could thereby prevent formation of inversions of the region between such sites. To distinguish between these two possibilities, we have constructed inversions of two non-permissive intervals by means of phage P22-mediated transduction crosses. These crosses generate inversions by simultaneous incorporation of two transduced fragments, each with a sequence that forms one join-point of the final inversion. We constructed inversions of the non-permissive intervals trp ('34) to his ('42) and his ('42) to cysA ('50). Strains with the constructed inversions are viable and grow normally. These results show that our previous failure to detect formation of these inversions by recombination between chromosomal sequences was not due to lethal effects of the final rearrangement. We infer that the "non-permissive" character of some chromosomal segments reflects the inability of the recombination system to perform the needed exchanges between inverse order sequences at particular sites. Apparently these mechanistic problems were circumvented by the transductional method used here to direct inversion formation.

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Coyne, J. A., W. Meyers, A. P. Crittenden e P. Sniegowski. "The fertility effects of pericentric inversions in Drosophila melanogaster." Genetics 134, n. 2 (1 giugno 1993): 487–96. http://dx.doi.org/10.1093/genetics/134.2.487.

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Abstract Heterozygotes for pericentric inversions are expected to be semisterile because recombination in the inverted region produces aneuploid gametes. Newly arising pericentric inversions should therefore be quickly eliminated from populations by natural selection. The occasional polymorphism for such inversions and their fixation among closely related species have supported the idea that genetic drift in very small populations can overcome natural selection in the wild. We studied the effect of 7 second-chromosome and 30 third-chromosome pericentric inversions on the fertility of heterokaryotypic Drosophila melanogaster females. Surprisingly, fertility was not significantly reduced in many cases, even when the inversion was quite large. This lack of underdominance is almost certainly due to suppressed recombination in inversion heterozygotes, a phenomenon previously observed in Drosophila. In the large sample of third-chromosome inversions, the degree of underdominance depends far more on the position of breakpoints than on the inversion's length. Analysis of these positions shows that this chromosome has a pair of "sensitive sites" near cytological divisions 68 and 92: these sites appear to reduce recombination in a heterozygous inversion whose breakpoints are nearby. There may also be "sensitive sites" near divisions 31 and 49 on the second chromosome. Such sites may be important in initiating synapsis. Because many pericentric inversions do not reduce the fertility of heterozygotes, we conclude that the observed fixation or polymorphism of such rearrangements in nature does not imply genetic drift in very small populations.

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Più fonti

Tesi sul tema "Chromosome inversions"

Bhatt, Samarth. "Segregation analysis of paracentric inversions in human sperm". Montpellier 1, 2008. http://www.theses.fr/2008MON1T002.

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Les inversions paracentriques sont des anomalies chromosomiques généralement considérées comme inoffensives. Toutefois, des cas de porteurs de chromosomes remaniés issus d'inversions paracentriques ont été rapportés, soulignant la nécessité d'étudier le comportement méiotique de ces anomalies. Seules quelques études ont été pratiquées, utilisant la technique de fécondation croisée Homme-Hamster, le typage génétique des spermatozoïdes (sperm typing) ou l'hybridation in situ fluorescente (FISH) par marquages centromériques ou télomériques. Afin d'améliorer l'efficacité de l'étude méiotique des inversions paracentriques, nous avons développé l'utilisation des sondes BAC qui permettent une localisation chromosomique précise des points de cassures chromosomiques et l'identification de tous les produits méiotiques des inversions dans le sperme humain. Les points de cassures et la ségrégation méiotique de 3 inversions paracentriques, inv(5)(q13. 2q33. 1), inv(9)(q21. 2q34. 13) et inv(14)(q23. 2q32. 13), ont ainsi été déterminés. Les taux de recombinants observés dans ces 3 inversions varient de 3,72% à12,55%. Cette localisation des points de cassures et l'analyse des séquences d'ADN adjacentes sont essentielles pour mettre en évidence la formation de boucles d'inversion, pour déterminer le risque de recombinaison à terme, ainsi que pour étudier les mécanismes méiotiques de formation des recombinaisons. Ainsi, la présence de régions d'ADN riches en recombinaisons et en duplications inter-chromosomiques a été mise en évidence, en complément de la formation de recombinants chromosomiques. Par ailleurs, une nouvelle technique de FISH multi-couleurs 3D (3D MCB FISH) a été adaptée aux spermatozoïdes humains pour l'analyse in situ des ségrégations. Cette approche permet de visualiser in situ les inversions paracentriques et d'estimer la fréquence de tous les types de recombinants issus de boucles d'inversion, de recombinaisons U-loop ou de processus de cassure/fusion des chromatides-soeurs.

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Yue, Ying. "[Breakpoint analysis of human chromosome 3 inversions during hominoid evolution]". [S.l.] : [s.n.], 2005. http://deposit.ddb.de/cgi-bin/dokserv?idn=976057794.

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Chan, David Yiu Leung. "Analysis of artificial chromosomes and factors affecting stability in murine and human cultured and embryonic stem cells". Thesis, University of Oxford, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.568074.

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Human Artificial Chromosomes (HAC) are fascinating extrachromosomal molecules that stay independently from the host genome and are capable of segregating as efficiently as endogenous chromosomes. It has been proven that HAC are potential tools for both basic chromosome behavioural research and agents for gene therapy purposes. My DPhil project is divided into two main themes. The first theme was to develop a novel artificial chromosome in mouse embryonic stem cells. The second theme was to understand the factors affecting chromosome stability which may also affect the efficiency of artificial chromosome formation. so that our protocol for better HAC preparation can be refined. There are six results chapters in my thesis. The first three chapters described how I developed human artificial chromosomes in mouse embryonic stem cells. Initially, vectors containing a long stretch of human alphoid DNA were delivered to mouse cells using the Herpes Simplex Virus-I (HSV-l) amplicon system but the efficiency was low. Next, mouse pericentromeric and centromeric DNAs were employed for mouse artificial chromosome (MAC) via HSV-l system. However, the efficiency remained the same. Finally, I used the Microcell-Mediated Chromosome Transfer (MMCT) system to transfer HAC from HTl 080 cells into mouse ES cells and successfully established HAC in ES which were highly stable. The results obtained in this first part of my thesis suggested that to increase HAC formation efficiency it would be necessary to improve the techniques of HSV-I delivery and MMCT. Moreover, it would also be important to better characterize factors affecting chromosome behaviour. The last three results chapters focus on factors affecting chromosomes stability and improving the HSV -1 delivery system and MMCT. I undertook an in vivo study of whole cell fusion experiments with the aid of live cell irnaging system, and found that histone H2B proteins underwent a dynamic assembly/disassembly processes. Live cell imaging of MMCT suggested that the microcell delivery is a very slow process and the results may lead to a refinement of the MMCT protocol. I found it is possible to generate a single HAC using two HSV-l amplicons containing two different constructs, potentially doubling the HSV-l HAC capacity from 150 kb to 300 kb. The last chapter illustrated how the expression of non- coding centromeric satellites impaired chromosome stability in both human cultured and human embryonic stem cells. The findings revealed that non-coding centromeric RNA plays an important role on chromosome stability that might be important for artificial chromosome development.

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Mautras, Albert. "Les inversions paracentriques du chromosome sept : à propos de deux observations". Bordeaux 2, 1989. http://www.theses.fr/1989BOR25067.

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Nanassy, Oliver Zoltan. "Genetic and biochemical analysis of the Salmonella typhimurium Hin DNA recombinase /". Thesis, Connect to this title online; UW restricted, 1999. http://hdl.handle.net/1773/11525.

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Rocha, Felipe Bastos 1981. "Pigmentação em Drosophila mediopunctata : plasticidade fenotipica e herdabilidade". [s.n.], 2007. http://repositorio.unicamp.br/jspui/handle/REPOSIP/316971.

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Orientador: Louis Bernard Klaczko
Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia
Made available in DSpace on 2018-08-08T11:40:37Z (GMT). No. of bitstreams: 1 Rocha_FelipeBastos_M.pdf: 1521732 bytes, checksum: 2e105d0f1d7044bc42e2f93125f6ac49 (MD5) Previous issue date: 2007
Resumo: Drosophila mediopunctata é uma espécie pertencente ao grupo tripunctata, que tem como traço marcante um padrão de pigmentação abdominal, sob a forma de três pintas na região mediana dos últimos tergitos. Nesta espécie, este padrão é variável, havendo indivíduos com quatro fenótipos, que vão de zero a três pintas. Já se observou que esta variação tem determinação genética, com marcada influência do cromossomo II, e alta plasticidade fenotípica em resposta à temperatura de desenvolvimento. Neste trabalho, buscou-se caracterizar parte destas duas fontes de variação. Por um lado, foram estudadas as normas de reação da pigmentação a um gradiente térmico, investigando-se classes fenotípicas contrastantes. Devido ao desenho experimental, que buscou separar os efeitos desta variável de um possível papel das inversões do cromossomo II, foi possível evidenciar um forte efeito das classes fenotípicas utilizadas sobre a resposta das estirpes ao gradiente térmico, independente do cariótipo. Foram descritos, por polinômios, dois tipos de norma de reação relacionados ao fenótipo, ambos com forma de parábola, mas diferindo em relação ao coeficiente de curvatura. O grupo de estirpes de pigmentação clara apresentou uma curva côncava e o grupo escuro uma curva convexa. A norma de reação da taxa de desenvolvimento de ovo a adulto foi caracterizada a partir do mesmo procedimento. Entretanto, apesar dos efeitos significativos do cariótipo e da classe fenotípica, a homogeneidade das normas de reação descritas por regressões lineares não possibilitou uma interpretação clara destes efeitos. A plasticidade do caráter também foi investigada quanto ao período de desenvolvimento termo-sensível. Assim, foi possível determinar a porção final da fase de pupa como o período no qual ocorre a influência da temperatura sobre o fenótipo de pintas do adulto. Por outro lado, em relação à determinação genética do caráter, foram obtidas estimativas de herdabilidade para o número de pintas abdominais, em condições quase naturais. Visando estabelecer um parâmetro de comparação com outros trabalhos, foi estimada a herdabilidade do tamanho do tórax a partir do mesmo material. Os resultados deste experimento, apresentaram grande contraste entre os dois traços: as estimativas foram baixas ou não significativas para o tamanho do tórax e, em geral, altas e significativas para o número de pintas
Abstract: Drosophila mediopunctata belongs to the tripunctata species group, which has a typical abdomen pigmentation pattern, consisting of three dark spots in the last tergites. In this species, this pattern is variable, with the phenotypes ranging from zero to three spots. It has been noted that this variation has genetical determination, with strong influence from the second chromosome, and high phenotypic plasticity in response to the developmental temperature. In this work, we attempted to describe part of these two variation sources. On one side, the pigmentation reaction norm to a thermal gradient was studied, by investigating the influence of contrasting phenotypical classes. Given the experimental design, which was planned to separate the effects of this variable from a possible influence of the second chromosome inversions, it was possible to detect a strong effect of the phenotypical classes on the lineages response to the thermal gradient, independent of the kariotype. Two types of reaction norms, related to the phenotype, were detected and described by polynomial adjustment. Both had a parabolic shape, but with different curvature coefficients. The light pigmentation lineage group showed a concave curve, and the dark group had a convex curve. The reaction norm of development rate from egg to adult was described according to the same procedure. However, despite the significant effects of the karyotype and phenotypical classes, the homogeneity of reaction norms, described by linear regression, hindered a clear interpretation of these effects. The character plasticity was also investigated in respect to the developmental thermosensitive period. Thus, it was possible to determine that the period in which the temperature influence on the adult phenotype occurs is the last portion of the pupal phase. On another side, relative to the character genetic determination, heritability estimates for the number of abdominal spots were obtained, in nearly natural conditions. Aiming to establish a comparison parameter with other studies, the heritability of thorax length was estimated based on the same material. The results of this experiment reveal a great contrast between these trait estimates: for the thorax they were low or non-significant, and, in general, for the abdominal spot number, they were high and significant
Mestrado
Genetica Animal e Evolução
Mestre em Genética e Biologia Molecular

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Garmendia, Eva. "A Unified Multitude : Experimental Studies of Bacterial Chromosome Organization". Doctoral thesis, Uppsala universitet, Institutionen för medicinsk biokemi och mikrobiologi, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-332471.

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Bacteria are many, old and varied; different bacterial species have been evolving for millions of years and show many disparate life-styles and types of metabolism. Nevertheless, some of the characteristics regarding how bacteria organize their chromosomes are relatively conserved, suggesting that they might be both ancient and important, and that selective pressures inhibit their modification. This thesis aims to study some of these characteristics experimentally, assessing how changes affect bacterial growth, and how, after changing conserved features, bacteria might evolve. First, we experimentally tested what are the constraints on the horizontal transfer of a gene highly important for bacterial growth. Second, we investigated the significance of the location and orientation of a highly expressed and essential operon; and we experimentally evolved strains with suboptimal locations and orientations to assess how bacteria could adapt to these changes. Thirdly, we sought to understand the accessibility of different regions of the bacterial chromosome to engage in homologous recombination. And lastly, we constructed bacterial strains with chromosomal inversions to assess what effect the inversions had on growth rate, and how bacteria carrying costly inversions could evolve to reduce these costs. The results provide evidence for different selective forces acting to conserve these chromosome organizational traits. Accordingly, we found that evolutionary distance, functional conservation, suboptimal expression and impaired network connectivity of a gene can affect the successful transfer of genes between bacterial species. We determined that relative location of an essential and highly expressed operon is critical for supporting fast growth rate, and that its location seems to be more important than its orientation. We also found that both the location, and relative orientation of separated duplicate sequences can affect recombination rates between these sequences in different regions of the chromosome. Finally, the data suggest that the importance of having the two arms of a circular bacterial chromosome approximately equal in size is a strong selective force acting against certain type of chromosomal inversions.

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Todd, Roger Benedict. "Molecular analysis of a 7q inversion associated with myelodysplasia". Thesis, University College London (University of London), 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.248167.

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Fellmann, Florence. "Inversion paracentrique : marqueur ou anomalie ; a propos d'une inversion paracentrique du chromosome 13 transmise sur 5 generations d'une famille de 162 membres". Nancy 1, 1993. http://www.theses.fr/1993NAN11162.

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Nelson, Tanya N. "Molecular genetic analysis of human 8p inversion duplication chromosomes". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp02/NQ34598.pdf.

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Più fonti

Libri sul tema "Chromosome inversions"

Krimbas, Costas B. Drosophila subobscura: Biology, genetics, and inversion polymorphism. Hamburg: Kovač, 1993.

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McKinlay Gardner, R. J., e David J. Amor. Inversions. A cura di R. J. McKinlay Gardner e David J. Amor. Oxford University Press, 2018. http://dx.doi.org/10.1093/med/9780199329007.003.0009.

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Inversions are intrachromosomal structural rearrangements. The most common is the simple (or single) inversion. If the inversion coexists with another rearrangement in the same chromosome, it is a complex inversion. In an inversion, a segment of chromosome is switched 180 degrees. If this segment includes the centromere, this is a pericentric inversion; if not, it is a paracentric inversion. In principle, and almost always in practice, it is only the pericentric inversion that conveys an important genetic risk to carriers of the inversion: Their children may inherit a “recombinant” chromosome that would inevitably be imbalanced. This chapter considers these two type of inversions and discusses the degree of genetic risk that may—or may not—be associated.

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Drosophila inversion polymorphism. Boca Raton, Fla: CRC Press, 1992.

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Gale, William L. Sexual differentiation and steroid-induced sex inversion in Nile tilapia (Oreochromis niloticus): 1. Characterization of a gonadal androgen receptor : 2. Masculinization by immersion in methyldihydrotestosterone. 1996.

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McKinlay Gardner, R. J., e David J. Amor. Complex Chromosomal Rearrangements. A cura di R. J. McKinlay Gardner e David J. Amor. Oxford University Press, 2018. http://dx.doi.org/10.1093/med/9780199329007.003.0010.

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Complex chromosome rearrangements (CCRs) include most of the rearrangements that would not be accounted for as “straightforward” classical categories. They may be translocations with three or more segments involved; or they may comprise a mix of translocation and, for example, inversion. Some can be extraordinarily complex. CCRs are classified as types I–IV, most falling into the “least complex” type I category, while types II–IV are grouped as “exceptional CCRs.” Many unbalanced CCRs have arisen de novo and imply no increased reproductive risk. The identification of the clinically normal balanced CCR carrier is less frequent, and for these people, the reproductive risks can be very high.

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Frankham, Richard, Jonathan D. Ballou, Katherine Ralls, Mark D. B. Eldridge, Michele R. Dudash, Charles B. Fenster, Robert C. Lacy e Paul Sunnucks. Outbreeding depression is uncommon and predictable. Oxford University Press, 2017. http://dx.doi.org/10.1093/oso/9780198783398.003.0007.

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Crosses between populations within species sometimes result in reduced fitness, especially in F2 and later generations (outbreeding depression). The primary mechanisms causing outbreeding depression in crosses between populations are fixed chromosomal differences and adaptive genetic differences, especially for long-isolated populations. Outbreeding depression is usually observed after crossing populations with ploidy differences or fixed differences for translocations, inversions or centric fusions: the magnitudes are usually ploidy > translocations and monobrachial centric fusions > inversions and simple centric fusions. Populations adapted to different environments (but with the same karyotype) often exhibit outbreeding depression when crossed, especially in the F2 and later generations. Even if outbreeding depression occurs, it is often only temporary, as natural selection acts to remove it, especially in large populations.

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Capitoli di libri sul tema "Chromosome inversions"

Kirkpatrick, Mark, e Brian Barrett. "CHROMOSOME INVERSIONS, ADAPTIVE CASSETTES AND THE EVOLUTION OF SPECIES’ RANGES". In Invasion Genetics, 175–86. Chichester, UK: John Wiley & Sons, Ltd, 2016. http://dx.doi.org/10.1002/9781119072799.ch10.

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Miller, Orlando J., e Eeva Therman. "Clinical Importance of Translocations, Inversions, and Insertions". In Human Chromosomes, 239–54. New York, NY: Springer New York, 2001. http://dx.doi.org/10.1007/978-1-4613-0139-4_16.

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Kececioglu, John, e David Sankoff. "Efficient bounds for oriented chromosome inversion distance". In Combinatorial Pattern Matching, 307–25. Berlin, Heidelberg: Springer Berlin Heidelberg, 1994. http://dx.doi.org/10.1007/3-540-58094-8_26.

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Broman, Karl W., Naomichi Matsumoto, Sabrina Giglio, Christa Lese Martin, Jessica A. Roseberry, Orsetta Zuffardi, David H. Ledbetter e James L. Weber. "Common Long Human Inversion Polymorphism on Chromosome $8p$". In Institute of Mathematical Statistics Lecture Notes - Monograph Series, 237–46. Beachwood, OH: Institute of Mathematical Statistics, 2003. http://dx.doi.org/10.1214/lnms/1215091145.

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Ruggero, Katia, e Terence H. Rabbitts. "Pre-clinical Modelling of Chromosomal Translocations and Inversions". In Chromosomal Translocations and Genome Rearrangements in Cancer, 429–45. Cham: Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-19983-2_20.

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Khalafalla, Kareim, Pallav Sengupta, Mohamed Arafa, Ahmad Majzoub e Haitham Elbardisi. "Chromosomal Translocations and Inversion in Male Infertility". In Genetics of Male Infertility, 207–19. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-37972-8_12.

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Kiknadze, L. I., L. I. Gunderina, A. G. Istomina, V. D. Gusev e L. A. Nemytikova. "Similarity Analysis of Inversion Banding Sequences in Chromosomes of Chironomus Species (Breakpoint Phylogeny)". In Bioinformatics of Genome Regulation and Structure, 245–53. Boston, MA: Springer US, 2004. http://dx.doi.org/10.1007/978-1-4419-7152-4_26.

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Malissen, Marie, Candice McCoy, Dominique Blanc, Jeannine Trucy, Christian Devaux, Anne-Marie Schmitt-Verhulst, Frgnk Fitch, Leroy Hood e Bernard Malissen. "A Chromosomal Inversion Generates a Functional T Cell Receptor β Chain Gene". In Regulation of Immune Gene Expression, 177–83. Totowa, NJ: Humana Press, 1986. http://dx.doi.org/10.1007/978-1-4612-5014-2_16.

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Yokoi, Katsuyuki, Yoko Nakajima, Tamae Ohye, Hidehito Inagaki, Yoshinao Wada, Tokiko Fukuda, Hideo Sugie, Isao Yuasa, Tetsuya Ito e Hiroki Kurahashi. "Disruption of the Responsible Gene in a Phosphoglucomutase 1 Deficiency Patient by Homozygous Chromosomal Inversion". In JIMD Reports, 85–90. Berlin, Heidelberg: Springer Berlin Heidelberg, 2018. http://dx.doi.org/10.1007/8904_2018_108.

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Quinonez, Shane C., Andrea H. Seeley, Cindy Lam, Thomas W. Glover, Bruce A. Barshop e Catherine E. Keegan. "Paracentric Inversion of Chromosome 21 Leading to Disruption of the HLCS Gene in a Family with Holocarboxylase Synthetase Deficiency". In JIMD Reports, 55–61. Berlin, Heidelberg: Springer Berlin Heidelberg, 2016. http://dx.doi.org/10.1007/8904_2016_9.

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Atti di convegni sul tema "Chromosome inversions"

Soboleva, E. S., V. S. Fedorova, V. A. Burlak, M. V. Sharakhova e G. N. Artemov. "INVERSION POLYMORPHISM OF NATURAL POPULATIONS ANOPHELES BEKLEMISHEVI STEGNII ET KABANOVA IN WESTERN SIBERIA". In V International Scientific Conference CONCEPTUAL AND APPLIED ASPECTS OF INVERTEBRATE SCIENTIFIC RESEARCH AND BIOLOGICAL EDUCATION. Tomsk State University Press, 2020. http://dx.doi.org/10.17223/978-5-94621-931-0-2020-35.

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The geographical distribution and inversion polymorphism of malaria mosquitoes Anopheles beklemishevi Stegnii et Kabanova in the West Siberia were investigated. X chromosome homozygous cytotypes were defined by fluorescent in situ hybridization of microdissected DNA-probe, labeling the breakpoints region of X chromosome inversions. For the first time the samples, which are homozygous and hemizygous by inversions X1 и X2 were detected. Cytotypes representation and frequencies have not differences between northern and southern (Altay) population of the malaria mosquitoes.

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Richards, Stephen. "Molecular population genomics of chromosomal inversions inDrosophilapseudoobscura". In 2016 International Congress of Entomology. Entomological Society of America, 2016. http://dx.doi.org/10.1603/ice.2016.93635.

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Nowling, Ronald J., e Scott J. Emrich. "Detecting Chromosomal Inversions from Dense SNPs by Combining PCA and Association Tests". In BCB '18: 9th ACM International Conference on Bioinformatics, Computational Biology and Health Informatics. New York, NY, USA: ACM, 2018. http://dx.doi.org/10.1145/3233547.3233571.

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Huber, P., J. Dalmon, M. Laurent, G. Courtois, D. Thevenon e G. Marguerie. "CHARACTERIZATION OFTHE 5’FLANKING REGION FOR THE HUMAN FIBRINOGEN β GENE". In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1642889.

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Fibrinogen is coded by three separate genes located in a 50kb region of chromosome 4 and organized in a α - β - γ orientation with an inversion of the gene 3- A human genomic library was constructed using the EMBL4 phage and screened with cDNA probes coding for human fibrinogen Aα, Bβ and γ chains. Clones, covering the fibrinogen locus,were identified, and their organization was analyzed by means of hybridization and restriction mapping. Among these clones one recombinant phage containing the β gene and large 5’ and 3’ -flanking sequences was isolated.To identify the regulatory sequences Dpstream from the human β gene, a 1.5 kb fragment of the immediate 5’-flanking region was sequenced. The SI mapping experiments revealed three transcription initiation sites. PotentialTATA and CAAT sequences were identified upstream the initiation start points at the positions -21 and -58 from the first initiation start point.Comparison of this sequence with that previously reported for the same region upstream from the human γ gene revealed no significant homology which suggests that the potential promoting sequences of these genes are different. In contrast, comparison of the 5’flanking regions of human and rat β genes showed more than 80% homology for 142 bp upstream from the gene. This highly conserved region is a potential candidate for a regulatory sequence of the human β gene.To verify this activity, a β fibrinogen minigene was constructed by deletion of the internal part of the normal gene and including 3.4kb of the 5’flanking region and 1.4kb of the 3’flanking region. The minigene was transfected into HepG2, a human hepatoma cell line, to show whether the 5’flanking region of the human fibrinogen gene contains DNA sequences sufficient for efficient transcription in HepG2. Constructions of several parts of the sequenced 5’flanking region of the human β gene with the gene of the chloramphenical acetyl transferase have been also transfected in the HepG2 cells to determine the specificity of the gene expression and to localize the sequences controlling the transcription of the gene.

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