Journal articles on the topic 'Human chromosomes'
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1
Messier, P. E., R. Drouin, and C. L. Richer. "Electron microscopy of gold-labeled human and equine chromosomes." Journal of Histochemistry & Cytochemistry 37, no. 9 (September 1989): 1443–47. http://dx.doi.org/10.1177/37.9.2768813.
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We present an immunochemical technique for the detection of 5-bromo-2'-deoxyuridine (BrdU) incorporated discontinuously into the chromosomal DNA. A monoclonal anti-BrdU antibody and a protein A-gold complex were used to produce chromosome banding of human and equine chromosomes, specific for electron microscopy (EM). Well-defined bands, symmetry of sister chromatids, concordance between homologues, and band patterns similar to those observed by light microscopy facilitate chromosome identification and karyotyping. From prophase to late metaphase, chromosomes condense and bands appear to fuse. The fusion appears to be owing to chromatin reorganization. Our results underline the value of using immunogold reagents, which are ideal probes for antigen localization on chromosomes.
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Cornforth, Michael N., Karin M. Greulich-Bode, Bradford D. Loucas, Javier Arsuaga, Mariel Vázquez, Rainer K. Sachs, Martina Brückner, et al. "Chromosomes are predominantly located randomly with respect to each other in interphase human cells." Journal of Cell Biology 159, no. 2 (October 28, 2002): 237–44. http://dx.doi.org/10.1083/jcb.200206009.
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To test quantitatively whether there are systematic chromosome–chromosome associations within human interphase nuclei, interchanges between all possible heterologous pairs of chromosomes were measured with 24-color whole-chromosome painting (multiplex FISH), after damage to interphase lymphocytes by sparsely ionizing radiation in vitro. An excess of interchanges for a specific chromosome pair would indicate spatial proximity between the chromosomes comprising that pair. The experimental design was such that quite small deviations from randomness (extra pairwise interchanges within a group of chromosomes) would be detectable. The only statistically significant chromosome cluster was a group of five chromosomes previously observed to be preferentially located near the center of the nucleus. However, quantitatively, the overall deviation from randomness within the whole genome was small. Thus, whereas some chromosome–chromosome associations are clearly present, at the whole-chromosomal level, the predominant overall pattern appears to be spatially random.
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Csonka, E., I. Cserpan, K. Fodor, G. Hollo, R. Katona, J. Kereso, T. Praznovszky, et al. "Novel generation of human satellite DNA-based artificial chromosomes in mammalian cells." Journal of Cell Science 113, no. 18 (September 15, 2000): 3207–16. http://dx.doi.org/10.1242/jcs.113.18.3207.
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An in vivo approach has been developed for generation of artificial chromosomes, based on the induction of intrinsic, large-scale amplification mechanisms of mammalian cells. Here, we describe the successful generation of prototype human satellite DNA-based artificial chromosomes via amplification-dependent de novo chromosome formations induced by integration of exogenous DNA sequences into the centromeric/rDNA regions of human acrocentric chromosomes. Subclones with mitotically stable de novo chromosomes were established, which allowed the initial characterization and purification of these artificial chromosomes. Because of the low complexity of their DNA content, they may serve as a useful tool to study the structure and function of higher eukaryotic chromosomes. Human satellite DNA-based artificial chromosomes containing amplified satellite DNA, rDNA, and exogenous DNA sequences were heterochromatic, however, they provided a suitable chromosomal environment for the expression of the integrated exogenous genetic material. We demonstrate that induced de novo chromosome formation is a reproducible and effective methodology in generating artificial chromosomes from predictable sequences of different mammalian species. Satellite DNA-based artificial chromosomes formed by induced large-scale amplifications on the short arm of human acrocentric chromosomes may become safe or low risk vectors in gene therapy.
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Sajid, Atiqa, El-Nasir Lalani, Bo Chen, Teruo Hashimoto, Darren K. Griffin, Archana Bhartiya, George Thompson, Ian K. Robinson, and Mohammed Yusuf. "Ultra-Structural Imaging Provides 3D Organization of 46 Chromosomes of a Human Lymphocyte Prophase Nucleus." International Journal of Molecular Sciences 22, no. 11 (June 1, 2021): 5987. http://dx.doi.org/10.3390/ijms22115987.
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Three dimensional (3D) ultra-structural imaging is an important tool for unraveling the organizational structure of individual chromosomes at various stages of the cell cycle. Performing hitherto uninvestigated ultra-structural analysis of the human genome at prophase, we used serial block-face scanning electron microscopy (SBFSEM) to understand chromosomal architectural organization within 3D nuclear space. Acquired images allowed us to segment, reconstruct, and extract quantitative 3D structural information about the prophase nucleus and the preserved, intact individual chromosomes within it. Our data demonstrate that each chromosome can be identified with its homolog and classified into respective cytogenetic groups. Thereby, we present the first 3D karyotype built from the compact axial structure seen on the core of all prophase chromosomes. The chromosomes display parallel-aligned sister chromatids with familiar chromosome morphologies with no crossovers. Furthermore, the spatial positions of all 46 chromosomes revealed a pattern showing a gene density-based correlation and a neighborhood map of individual chromosomes based on their relative spatial positioning. A comprehensive picture of 3D chromosomal organization at the nanometer level in a single human lymphocyte cell is presented.
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Haig, David. "A brief history of human autosomes." Philosophical Transactions of the Royal Society of London. Series B: Biological Sciences 354, no. 1388 (August 29, 1999): 1447–70. http://dx.doi.org/10.1098/rstb.1999.0490.
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Comparative gene mapping and chromosome painting permit the tentative reconstruction of ancestral karyotypes. The modern human karyotype is proposed to differ from that of the most recent common ancestor of catarrhine primates by two major rearrangements. The first was the fission of an ancestral chromosome to produce the homologues of human chromosomes 14 and 15. This fission occurred before the divergence of gibbons from humans and other apes. The second was the fusion of two ancestral chromosomes to form human chromosome 2. This fusion occurred after the divergence of humans and chimpanzees. Moving further back in time, homologues of human chromosomes 3 and 21 were formed by the fission of an ancestral linkage group that combined loci of both human chromosomes, whereas homologues of human chromosomes 12 and 22 were formed by a reciprocal translocation between two ancestral chromosomes. Both events occurred at some time after our most recent common ancestor with lemurs. Less direct evidence suggests that the short and long arms of human chromosomes 8, 16 and 19 were unlinked in this ancestor. Finally, the most recent common ancestor of primates and artiodactyls is proposed to have possessed a chromosome that combined loci from human chromosomes 4 and 8p, a chromosome that combined loci from human chromosomes 16q and 19q, and a chromosome that combined loci from human chromosomes 2p and 20.
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Ghazizadeh, Mohammad, Yoshihiro Sasaki, Tatsuo Oguro, Shigeru Sato, Seiko Egawa, Kyoko Inoue, Akiko Adachi, Hajime Shimizu, and Oichi Kawanami. "A Novel Technique for Observing the Internal Ultrastructure of Human Chromosomes with Known Karyotype." Microscopy and Microanalysis 14, no. 4 (July 4, 2008): 357–61. http://dx.doi.org/10.1017/s143192760808063x.
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Observation of the internal ultrastructure of human chromosomes by transmission electron microscopy (TEM) has frequently been attempted in spite of the difficulties in detaching metaphase chromosome spreads from the glass slide for further processing. In this study we have used a method in which metaphase chromosome spreads were prepared on a flexible thermoplastic membrane (ACLAR) film. To assess chromosome identity, a diamidino-phenylindole staining and karyotying was first done using a conventional cytogenetic system. The chromosome spreads were then fixed with 1% osmium tetroxide, stained with freshly prepared 2% tannic acid, dehydrated, and flat-embedded in epoxy resin. The resin sheet was easily detachable and carried whole chromosome spreads. By this method, TEM observation of chromosomes from normal human lymphocytes allowed a thorough examination of the ultrastructure of centromeres, telomeres, fragile sites, and other chromosomal regions. Various ultrastructural patterns including thick electron dense boundaries, less dense internal regions, and extended chromatin loops at the periphery of the chromosomes were discernible. Application of the present method to chromosome research is expected to provide comprehensive information on the internal ultrastructure of different chromosomal regions in relation to function.
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Weier, Jingly F., Christy Ferlatte, Adolf Baumgartner, Ha Nam Nguyen, Beatrice A. Weier, and Heinz-Ulrich G. Weier. "Analysis of human invasive cytotrophoblasts demonstrates mosaic aneuploidy." PLOS ONE 18, no. 7 (July 21, 2023): e0284317. http://dx.doi.org/10.1371/journal.pone.0284317.
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A total of 24 chromosome-specific fluorescence in situ hybridization probes for interphase nucleus analysis were developed to determine the chromosomal content of individual human invasive cytotrophoblasts derived from in vitro cultured assays. At least 75% of invasive cytotrophoblasts were hyperdiploid and the total number of chromosomes ranged from 47 to 61. The results also demonstrated that these hyperdiploid invasive cytotrophoblasts showed significant heterogeneity. The most copy number gains were observed for chromosomes 13, 14, 15, 19, 21, and 22 with average copy number greater than 2.3. A parallel study using primary invasive cytotrophoblasts also showed a similar trend of copy number changes. Conclusively, 24-chromosome analysis of human non-proliferating cytotrophoblasts (interphase nuclei) was achieved. Hyperdiploidy and chromosomal heterogeneity without endoduplication in invasive cytotrophoblasts may suggest a selective advantage for invasion and short lifespan during normal placental development.
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Drouin, Régen, and Claude-Lise Richer. "High-resolution R-banding at the 1250-band level. II. Schematic representation and nomenclature of human RBG-banded chromosomes." Genome 32, no. 3 (June 1, 1989): 425–39. http://dx.doi.org/10.1139/g89-466.
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Detailed characterization of the RBG-banding pattern at the 1250-band level has been done after thymidine synchronization and block release with 5-bromo-2′-deoxyuridine (BrdU), which induces chromosome elongation and improves definition of chromosomal bands. Optimal conditions for the incorporation of BrdU and the use of the FPG (fluorochrome–photolysis–Giemsa) technique produced excellent band separation and band contrast even in highly elongated prophase chromosomes. Moreover, we did not observe lateral asymmetry in C-banded regions. The schematic representation of these elongated chromosomes in the 1250-band range per haploid set was prepared showing the relative position, the specific size, and the characteristic staining intensity for each band. To this idiogram was extended the International Standard Cytogenetic Nomenclature. This realistic idiogram should help in the preparation of R-banded prophase karyotypes and in the identification and localization of chromosomal rearrangements. Because differences exist between RBG and RHG bands, a brief comparative description of each RBG-banded chromosome is included. Moreover, a minute analysis of the banding pattern revealed that various parts of chromosomes contract differently. We also observed the presence of R-positive bands in heterochromatic regions of the short arms of the acrocentrics, and of chromosomes 1, 9, 16, and Y.Key words: high-resolution chromosome banding, R-banding, idiogram, dynamic bandings, prophase chromosomes, chromosome banding by BrdU incorporation.
9
Ibraimov, Abyt. "The origin of the human karyotype: its uniqueness, causes and effects." Current Research in Biochemistry and Molecular Biology 2, no. 1 (January 7, 2020): 9–20. http://dx.doi.org/10.33702/crbmb.2020.1.1.2.
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As is known, the diploid number of human chromosomes is 46, while in other higher primates, such as chimpanzees and gorillas, this number is 48. It has been established that a decrease in the number of chromosomes by two in humans is a result of the fusion of two autosomes into one chromosome in his karyotype ancestors. However, why such changes in chromosomes occurred among the highest primates in humans, their uniqueness, causes and consequences have not yet become the subject of special studies. We believe that the transition from 48 to 46 chromosomes, as well as changes in the composition, localization and amount of chromosomal heterochromatin regions in the karyotype of the ancestors of modern man turned out to be crucial in his formation as a biological species with all the ensuing consequences.
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Escobar, H., I. Nolte, and N. Reimann-Berg. "Relevance of chromosome 13 aberrations in canine tumours." Tierärztliche Praxis Ausgabe K: Kleintiere / Heimtiere 40, no. 04 (2012): 267–70. http://dx.doi.org/10.1055/s-0038-1623649.
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SummaryFor human tumours there are many reports documenting the correlation between chromosome aberrations and tumour entities. Due to the complex canine karyotypic pattern (78 chromosomes), cytogenetic studies of tumours of the dog are rare. However, the reports in the literature show, that canine chromosome 13 (CFA 13) is predominantly involved in chromosomal changes. Interestingly, CFA 13 shows high homology to regions on the human chromosomes 4 (HSA 4) and 8 (HSA 8), which harbour the proto-oncogenes c-KIT and c-MYC. Both of these genes are involved in the development and progression of some human and canine tumour diseases.
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Neeru, Neeru, Anita Bhatnagar, and Abhay Singh Yadav. "A study of constitutive heterochromatin and NOR banding in three species of Indian major carps from the State of Haryana, India." Journal of Applied and Natural Science 10, no. 2 (June 1, 2018): 535–39. http://dx.doi.org/10.31018/jans.v10i2.1731.
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Cytogenetic survey of fishes becomes increasingly important to establish chromosomal relation between the teleosts, to have a glimpse of the relation between chromosomal evolution and differentiation of vertebrate species. In the present study, Chromosome banding studies was done in three species of carps i.e. Catla catla (Hamilton, 1822), Labeo rohita (Hamilton, 1822) and Cirrhinus mrigala (Hamilton, 1822). Diploid chromosome number 50 was observed in all 3 species of carps. The chromosomes of C. catla, L. rohita and C. mrigala showed constitutive heterochromatin at telomeric and centromeric regions of chromosomes. The Ag-NOR (Argyrophilic-Nucleolus Organizer Region) bands were observed on homologous chromosome pair number 11 in C. catla, 15th chromosome pair in L. rohita. In C. mrigala, the Ag- NOR staining elucidated the presence of darkly stained NORs on the terminal region of the long arms of one of the chromosome. Another homologue of this chromosome pair could not be localized due to scattering of chromosomes. The results depict that variation in ecological conditions with time due to human activities can not only affect the chromosomal number but also chromosomal morphology.
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Panova, A. V., E. D. Nekrasov, M. A. Lagarkova, S. L. Kiselev, and A. N. Bogomazova. "Late Replication of the Inactive X Chromosome Is Independent of the Compactness of Chromosome Territory in Human Pluripotent Stem Cells." Acta Naturae 5, no. 2 (June 15, 2013): 54–61. http://dx.doi.org/10.32607/20758251-2013-5-2-54-61.
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Dosage compensation of the X chromosomes in mammals is performed via the formation of facultative heterochromatin on extra X chromosomes in female somatic cells. Facultative heterochromatin of the inactivated X (Xi), as well as constitutive heterochromatin, replicates late during the S-phase. It is generally accepted that Xi is always more compact in the interphase nucleus. The dense chromosomal folding has been proposed to define the late replication of Xi. In contrast to mouse pluripotent stem cells (PSCs), the status of X chromosome inactivation in human PSCs may vary significantly. Fluorescence in situ hybridization with a whole X-chromosome-specific DNA probe revealed that late-replicating Xi may occupy either compact or dispersed territory in human PSCs. Thus, the late replication of the Xi does not depend on the compactness of chromosome territory in human PSCs. However, the Xi reactivation and the synchronization in the replication timing of X chromosomes upon reprogramming are necessarily accompanied by the expansion of X chromosome territory.
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van Dekken, H., D. Pinkel, J. Mullikin, B. Trask, G. van den Engh, and J. Gray. "Three-dimensional analysis of the organization of human chromosome domains in human and human-hamster hybrid interphase nuclei." Journal of Cell Science 94, no. 2 (October 1, 1989): 299–306. http://dx.doi.org/10.1242/jcs.94.2.299.
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This report describes the intranuclear organization of chromosomes in human-hamster hybrid nuclei and in human cell nuclei. The target chromosomes were stained using in situ hybridization with biotinylated, chromosome-specific DNA probes. Bound probe was detected with fluorescein-avidin. Hybridizations were performed to fixed nuclei in aqueous suspension in order to preserve their three-dimensional morphology. Total nuclear DNA was stained with DAPI. Three-dimensional information about the organization of DNA and probe within the nucleus was obtained by optical sectioning. The human chromosomes in human-hamster hybrid nuclei were found to be confined to ‘domains’ that were maintained during the cell cycle. Different spatial localization patterns of the human chromosomes were seen in interphase nuclei of two different hybrid cell lines. The positions of chromosome-specific repetitive sequences in human fibroblast interphase nuclei were also studied using probes for the telomeric region of chromosome 1p (1p36), the centromeric region of chromosome 9 (9q12) and the long arm of the Y chromosome (Yq12). These studies showed that the two 1p telomeric loci are located near the nuclear surface. The chromosome 9 centromeric loci are similarly located. Simultaneous hybridization of the chromosome 1 telomeric probe (target size approximately 200 kb; b, base) and the Y-specific probe (target size greater than 2Mb), demonstrate that the binding sites of the two probes can be distinguished in the same nucleus on the basis of domain size.
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Rudd, M. Katharine, Robert W. Mays, Stuart Schwartz, and Huntington F. Willard. "Human Artificial Chromosomes with Alpha Satellite-Based De Novo Centromeres Show Increased Frequency of Nondisjunction and Anaphase Lag." Molecular and Cellular Biology 23, no. 21 (November 1, 2003): 7689–97. http://dx.doi.org/10.1128/mcb.23.21.7689-7697.2003.
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ABSTRACT Human artificial chromosomes have been used to model requirements for human chromosome segregation and to explore the nature of sequences competent for centromere function. Normal human centromeres require specialized chromatin that consists of alpha satellite DNA complexed with epigenetically modified histones and centromere-specific proteins. While several types of alpha satellite DNA have been used to assemble de novo centromeres in artificial chromosome assays, the extent to which they fully recapitulate normal centromere function has not been explored. Here, we have used two kinds of alpha satellite DNA, DXZ1 (from the X chromosome) and D17Z1 (from chromosome 17), to generate human artificial chromosomes. Although artificial chromosomes are mitotically stable over many months in culture, when we examined their segregation in individual cell divisions using an anaphase assay, artificial chromosomes exhibited more segregation errors than natural human chromosomes (P < 0.001). Naturally occurring, but abnormal small ring chromosomes derived from chromosome 17 and the X chromosome also missegregate more than normal chromosomes, implicating overall chromosome size and/or structure in the fidelity of chromosome segregation. As different artificial chromosomes missegregate over a fivefold range, the data suggest that variable centromeric DNA content and/or epigenetic assembly can influence the mitotic behavior of artificial chromosomes.
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Tamang, Sonam. "Principles and Applications of Fetal Chromosome Number and Structure Analysis." Sriwijaya Journal of Obstetrics and Gynecology 1, no. 2 (December 20, 2023): 39–43. http://dx.doi.org/10.59345/sjog.v1i2.83.
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A crucial diagnostic technique employed in prenatal diagnosis is examining the quantity and arrangement of fetal chromosomes. The fundamental premise of this study is to determine the chromosomal count in the fetal cells and detect any genetic or chromosomal abnormalities that may be present. A total of 46 chromosomes are typically present in the human body, organized into 23 pairs. These pairs include one pair of sex chromosomes and 22 pairs of autosomal chromosomes. This study enables the identification of chromosomal abnormalities, such as trisomy (the presence of an additional chromosome) and monosomy (the absence of a chromosome), which can have an impact on the health of the fetus. In addition to determining the number of chromosomes, this examination can also detect structural chromosome abnormalities like translocations, deletions, and duplications, which might potentially affect the health of the fetus. This investigation's findings provide significant insights to both patients and clinicians, enabling them to make more informed choices about continuing the pregnancy and receiving appropriate medical attention if genetic abnormalities are detected. This study can also be utilized for the identification of particular genetic illnesses associated with specific gene mutations, thereby aiding in treatment strategizing and postnatal readiness.
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Watkins, PC, R. Eddy, Y. Fukushima, MG Byers, EH Cohen, WR Dackowski, RM Wydro, and TB Shows. "The gene for protein S maps near the centromere of human chromosome 3." Blood 71, no. 1 (January 1, 1988): 238–41. http://dx.doi.org/10.1182/blood.v71.1.238.238.
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Abstract Two different mapping approaches were used to determine the human chromosomal location of the gene for protein S. A human protein S cDNA was used as a hybridization probe to analyze a panel of somatic cell hybrids containing different human chromosomes. Cosegregation of protein S-specific DNA restriction fragments with human chromosome 3 was observed. Three cell hybrids containing only a portion of chromosome 3 were analyzed in order to further localize protein S. Based on the somatic cell hybrid analysis, protein S is assigned to a region of chromosome 3 that contains a small part of the long arm and short arm of the chromosome including the centromere (3p21----3q21). In situ hybridization of the protein S cDNA probe to human metaphase chromosomes permitted a precise localization of protein S to the region of chromosome 3 immediately surrounding the centromere (3p11.1---- 3q11.2). Protein S is the first protein involved in blood coagulation that has been mapped to human chromosome 3.
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Watkins, PC, R. Eddy, Y. Fukushima, MG Byers, EH Cohen, WR Dackowski, RM Wydro, and TB Shows. "The gene for protein S maps near the centromere of human chromosome 3." Blood 71, no. 1 (January 1, 1988): 238–41. http://dx.doi.org/10.1182/blood.v71.1.238.bloodjournal711238.
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Two different mapping approaches were used to determine the human chromosomal location of the gene for protein S. A human protein S cDNA was used as a hybridization probe to analyze a panel of somatic cell hybrids containing different human chromosomes. Cosegregation of protein S-specific DNA restriction fragments with human chromosome 3 was observed. Three cell hybrids containing only a portion of chromosome 3 were analyzed in order to further localize protein S. Based on the somatic cell hybrid analysis, protein S is assigned to a region of chromosome 3 that contains a small part of the long arm and short arm of the chromosome including the centromere (3p21----3q21). In situ hybridization of the protein S cDNA probe to human metaphase chromosomes permitted a precise localization of protein S to the region of chromosome 3 immediately surrounding the centromere (3p11.1---- 3q11.2). Protein S is the first protein involved in blood coagulation that has been mapped to human chromosome 3.
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Journal, Baghdad Science. "Chromosomal aberrations and N-ras activation in human larynx carcinoma cell line Hep-2." Baghdad Science Journal 5, no. 3 (September 7, 2008): 346–52. http://dx.doi.org/10.21123/bsj.5.3.346-352.
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In the present study, cytogenetic and molecular techniques were conducted to detect the chromosomal aneuploidy and the involvement of N and H genes in squamous larynx carcinoma cell line Hep-2.Our results showed that numerical and structural abnormalities were involved in larynx cancer Hep-2.The total number of chromosomes ranging from tripolyploidy in passage187to more than that in passage207.The more frequent chromosomes involved in numerical aberrations were chromosomes1,7,16,17 and 18. Structural chromosomal aberrations were also detected.Deletion of short arm was detected in chromosome 1(del 1p) and the long arm of chromosome 1(del 1q)and 6(del 6q).Gaining on short arms were also recorded in chromosomes 3(3p+) and 12(12p+).At the molecular level,one allele of N-ras proto-oncogene was found deleted in the location 61 in passage 187 and complete deletion of both locations in passage 207.These findings reflex a great genomic instability in the the tumor model used in this study. Also the results confirmed the multistages theory in cancer arising.
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Al-Faisal, Abdul Hussain M., Amal M. Ali, and Nahi Y. Yassen. "Chromosomal aberrations and N-ras activation in human larynx carcinoma cell line Hep-2." Baghdad Science Journal 5, no. 3 (September 7, 2008): 346–52. http://dx.doi.org/10.21123/bsj.2008.5.3.346-352.
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In the present study, cytogenetic and molecular techniques were conducted to detect the chromosomal aneuploidy and the involvement of N and H genes in squamous larynx carcinoma cell line Hep-2.Our results showed that numerical and structural abnormalities were involved in larynx cancer Hep-2.The total number of chromosomes ranging from tripolyploidy in passage187to more than that in passage207.The more frequent chromosomes involved in numerical aberrations were chromosomes1,7,16,17 and 18. Structural chromosomal aberrations were also detected.Deletion of short arm was detected in chromosome 1(del 1p) and the long arm of chromosome 1(del 1q)and 6(del 6q).Gaining on short arms were also recorded in chromosomes 3(3p+) and 12(12p+).At the molecular level,one allele of N-ras proto-oncogene was found deleted in the location 61 in passage 187 and complete deletion of both locations in passage 207.These findings reflex a great genomic instability in the the tumor model used in this study. Also the results confirmed the multistages theory in cancer arising.
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Kim, Jaebum, Marta Farré, Loretta Auvil, Boris Capitanu, Denis M. Larkin, Jian Ma, and Harris A. Lewin. "Reconstruction and evolutionary history of eutherian chromosomes." Proceedings of the National Academy of Sciences 114, no. 27 (June 19, 2017): E5379—E5388. http://dx.doi.org/10.1073/pnas.1702012114.
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Whole-genome assemblies of 19 placental mammals and two outgroup species were used to reconstruct the order and orientation of syntenic fragments in chromosomes of the eutherian ancestor and six other descendant ancestors leading to human. For ancestral chromosome reconstructions, we developed an algorithm (DESCHRAMBLER) that probabilistically determines the adjacencies of syntenic fragments using chromosome-scale and fragmented genome assemblies. The reconstructed chromosomes of the eutherian, boreoeutherian, and euarchontoglires ancestor each included >80% of the entire length of the human genome, whereas reconstructed chromosomes of the most recent common ancestor of simians, catarrhini, great apes, and humans and chimpanzees included >90% of human genome sequence. These high-coverage reconstructions permitted reliable identification of chromosomal rearrangements over ∼105 My of eutherian evolution. Orangutan was found to have eight chromosomes that were completely conserved in homologous sequence order and orientation with the eutherian ancestor, the largest number for any species. Ruminant artiodactyls had the highest frequency of intrachromosomal rearrangements, and interchromosomal rearrangements dominated in murid rodents. A total of 162 chromosomal breakpoints in evolution of the eutherian ancestral genome to the human genome were identified; however, the rate of rearrangements was significantly lower (0.80/My) during the first ∼60 My of eutherian evolution, then increased to greater than 2.0/My along the five primate lineages studied. Our results significantly expand knowledge of eutherian genome evolution and will facilitate greater understanding of the role of chromosome rearrangements in adaptation, speciation, and the etiology of inherited and spontaneously occurring diseases.
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Earnshaw, W. C., and C. A. Cooke. "Distribution and function of non-histone proteins in human chromosomes." Proceedings, annual meeting, Electron Microscopy Society of America 50, no. 1 (August 1992): 556–57. http://dx.doi.org/10.1017/s0424820100123180.
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The role of non-histone proteins in the structure and movements of mitotic chromosomes remains poorly understood. We describe here experiments aimed at characterization of the distribution of two very different classes of these proteins. The first is composed of integral components of the centromere (or primary constriction). The second class consists of proteins that we have termed “chromosome passenger proteins”. These proteins are chromosomal during most of the cell cycle, but appear to be associated with the cytoskeleton during anaphase and telophase.The centromere regions of chromosomes perform three essential functions in mitosis. (1) They form the site of attachment of the chromosomes to the mitotic spindle. (2) They contain the mechanochemical motor molecules that are responsible for the movements of the chromosomes along microtubules. (3) They regulate the pairing of sister chromatids during mitosis. The first two of these mitotic functions are properties of a disk-shaped structural specialization, the kinetochore, which is located at the surface of the centromeric heterochromatin.
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Kapoor, Priya, and Lori Frappier. "EBNA1 Partitions Epstein-Barr Virus Plasmids in Yeast Cells by Attaching to Human EBNA1-Binding Protein 2 on Mitotic Chromosomes." Journal of Virology 77, no. 12 (June 15, 2003): 6946–56. http://dx.doi.org/10.1128/jvi.77.12.6946-6956.2003.
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ABSTRACT Epstein-Barr virus (EBV) episomal genomes are stably maintained in human cells and are partitioned during cell division by mitotic chromosome attachment. Partitioning is mediated by the viral EBNA1 protein, which binds both the EBV segregation element (FR) and a mitotic chromosomal component. We previously showed that the segregation of EBV-based plasmids can be reconstituted in Saccharomyces cerevisiae and is absolutely dependent on EBNA1, the EBV FR sequence, and the human EBNA1-binding protein 2 (EBP2). We have now used this yeast system to elucidate the functional contribution of human EBP2 to EBNA1-mediated plasmid partitioning. Human EBP2 was found to attach to yeast mitotic chromosomes in a cell cycle-dependent manner and cause EBNA1 to associate with the mitotic chromosomes. The domain of human EBP2 that binds both yeast and human chromosomes was mapped and shown to be functionally distinct from the EBNA1-binding domain. The functionality and localization of human EBP2 mutants and fusion proteins indicated that the attachment of EBNA1 to mitotic chromosomes is crucial for EBV plasmid segregation in S. cerevisiae, as it is in humans, and that this is the contribution of human EBP2. The results also indicate that plasmid segregation in S. cerevisiae can occur through chromosome attachment.
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Hausmann, Michael, Gertrud Dudin, Jacob A. Aten, and Rainer Heilig. "Slit Scan Flow Cytometry Of Isolated Chromosomes Following Fluorescence Hybridization: An Approach Of Online Screening For Specific Chromosomes And Chromosome Translocations." Zeitschrift für Naturforschung C 46, no. 5-6 (June 1, 1991): 433–41. http://dx.doi.org/10.1515/znc-1991-5-616.
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The recently developed methods of non radioactive in situ hybridization of chromosomes offer new aspects for chromosome analysis. Fluorescent labelling of hybridized chromosomes or chromosomal subregions allows to facilitate considerably the detection of specific chromosomal abnormalities. Formany biomedical applications (e.g. biological dosimetry in the low dose range), a fast scoring for aberrations (e.g. dicentrics or translocations) in required. Here, we present an approach depending on fluorescence in situ hybridization of isolated suspension chromosomes that indicates the feasibility of a rapid screening for specific chromosomes or translocations by slit scan flow cytometry. Chromosomes of a Chinese hamster x human hybrid cell line were hybridized in suspension with biotinylated human genomic DNA . This DNA was decorated with FITC by a double antibody system against biotin. For flow cytometry the chromosomes were stabilized with ethanol and counterstained with DAPI or propidium iodide (PI). An experimental data set of several hundred double profiles was obtained by two parameter slit scan flow cytometry and evaluated automatically. The evaluation algorithm developed allowed a classification of chromosomes according to the number of centromeres and their chromosomal positions in less than 1 msec per individual profile. Approximately 20% of the measured DAPI profiles showed a bimodal distribution with a significant centromeric dip indicating a “ normal” chromosomal morphology and a correct alignment in the flow system. In many cases, profiles of a “normal” bimodal fluorescence distribution of the DNA stain (DAPI, PI) were correlated with a “ normal” FITC profile. Due to their centromeric indices these profiles agreed well to the expected human chromosomes of the cell line. In some cases of “ normal” DAPI (PI) profiles, “aberrant” FITC profiles were observed. These were interpreted as interspecies translocation chromosomes. For all results, there was a good agreement between flow cytometry and microscopic observations (digital image analysis)
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Sun, Xiaochao, Bin Yang, and Qunye Zhang. "Analysis of Inter-Chromosomal Distribution of Disease-Related Genes in Human Genome." Current Protein & Peptide Science 21, no. 11 (December 31, 2020): 1068–77. http://dx.doi.org/10.2174/1389203721666200426233158.
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: Many studies have shown that the spatial distribution of genes within a single chromosome exhibits distinct patterns. However, little is known about the characteristics of inter-chromosomal distribution of genes (including protein-coding genes, processed transcripts and pseudogenes) in different genomes. In this study, we explored these issues using the available genomic data of both human and model organisms. Moreover, we also analyzed the distribution pattern of protein-coding genes that have been associated with 14 common diseases and the insert/deletion mutations and single nucleotide polymorphisms detected by whole genome sequencing in an acute promyelocyte leukemia patient. We obtained the following novel findings. Firstly, inter-chromosomal distribution of genes displays a nonstochastic pattern and the gene densities in different chromosomes are heterogeneous. This kind of heterogeneity is observed in genomes of both lower and higher species. Secondly, protein-coding genes involved in certain biological processes tend to be enriched in one or a few chromosomes. Our findings have added new insights into our understanding of the spatial distribution of genome and disease- related genes across chromosomes. These results could be useful in improving the efficiency of disease-associated gene screening studies by targeting specific chromosomes.
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Liehr, Thomas. "From Human Cytogenetics to Human Chromosomics." International Journal of Molecular Sciences 20, no. 4 (February 14, 2019): 826. http://dx.doi.org/10.3390/ijms20040826.
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Background: The concept of “chromosomics” was introduced by Prof. Uwe Claussen in 2005. Herein, the growing insights into human chromosome structure finally lead to a “chromosomic view” of the three-dimensional constitution and plasticity of genes in interphase nuclei are discussed. This review is dedicated to the memory of Prof. Uwe Claussen (30 April 1945–20 July 2008). Recent findings: Chromosomics is the study of chromosomes, their three-dimensional positioning in the interphase nucleus, the consequences from plasticity of chromosomal subregions and gene interactions, the influence of chromatin-modification-mediated events on cells, and even individuals, evolution, and disease. Progress achieved in recent years is summarized, including the detection of chromosome-chromosome-interactions which, if damaged, lead to malfunction and disease. However, chromosomics in the Human Genetics field is not progressing presently, as research interest has shifted from single cell to high throughput, genomic approaches. Conclusion: Chromosomics and its impact were predicted correctly in 2005 by Prof. Claussen. Although some progress was achieved, present reconsiderations of the role of the chromosome and the single cell in Human Genetic research are urgently necessary.
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Zhegalova, Irina V., Petr A. Vasiluev, Ilya M. Flyamer, Anastasia S. Shtompel, Eugene Glazyrina, Nadezda Shilova, Marina Minzhenkova, et al. "Trisomies Reorganize Human 3D Genome." International Journal of Molecular Sciences 24, no. 22 (November 7, 2023): 16044. http://dx.doi.org/10.3390/ijms242216044.
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Trisomy is the presence of one extra copy of an entire chromosome or its part in a cell nucleus. In humans, autosomal trisomies are associated with severe developmental abnormalities leading to embryonic lethality, miscarriage or pronounced deviations of various organs and systems at birth. Trisomies are characterized by alterations in gene expression level, not exclusively on the trisomic chromosome, but throughout the genome. Here, we applied the high-throughput chromosome conformation capture technique (Hi-C) to study chromatin 3D structure in human chorion cells carrying either additional chromosome 13 (Patau syndrome) or chromosome 16 and in cultured fibroblasts with extra chromosome 18 (Edwards syndrome). The presence of extra chromosomes results in systematic changes of contact frequencies between small and large chromosomes. Analyzing the behavior of individual chromosomes, we found that a limited number of chromosomes change their contact patterns stochastically in trisomic cells and that it could be associated with lamina-associated domains (LAD) and gene content. For trisomy 13 and 18, but not for trisomy 16, the proportion of compacted loci on a chromosome is correlated with LAD content. We also found that regions of the genome that become more compact in trisomic cells are enriched in housekeeping genes, indicating a possible decrease in chromatin accessibility and transcription level of these genes. These results provide a framework for understanding the mechanisms of pan-genome transcription dysregulation in trisomies in the context of chromatin spatial organization.
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Shetty, Nirmalchandra K. "Inheritance of Chromosomes, Sex Determination, and the Human Genome." Gender and the Genome 2, no. 1 (January 2018): 16–26. http://dx.doi.org/10.1177/2470289718787131.
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Who is the determining factor for the sex of the offspring—mother, father, or both parents? This fundamental hypothesis proposes a new model of sex determination, challenging the existing dogma that the male Y chromosome of the father is the sole determinant of the sex of the offspring. According to modern science, the 3 X chromosomes (male XY and female XX) are assumed to be similar, and the sex of the offspring is determined after the zygote is formed. In contrast to this, the new hypothesis based on theoretical research proposes that the 3 X chromosomes can be differentiated, based on the presence of Barr bodies. The first X in female XX chromosomes and X in male XY chromosomes are similar as they lack Barr body and are hereby denoted as ‘X’ and referred to as ancestral chromosomes. The second X chromosome in the female cells which is a Barr body, denoted as X, is different. This X chromosome along with the Y chromosome are referred to as parental chromosomes. Sperm with a Y chromosome can only fuse with an ovum containing the ‘X’ chromosome. Similarly, sperm with the ‘X’ chromosome can only fuse with an ovum containing the X chromosome. Cell biology models of gametogenesis and fertilization were simulated with the new hypothesis model and assessed. Only chromosomes that participated in recombination could unite to form the zygote. This resulted in a paradigm shift in our understanding of sex determination, as both parents were found to be equally responsible for determining the sex of the offspring. The gender of the offspring is determined during the prezygotic stage itself and is dependent on natural selection. A new dimension has been given to inheritance of chromosomes. This new model also presents a new nomenclature for pedigree charts. This work of serendipity may contribute to future research in cell biology, gender studies, genome analysis, and genetic disorders including cancer.
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Flora Bai, B., A. Sujithra, C. Padhiar, P. Arjun, and A. Wilson Aruni Santhosh Kumar. "Fraccaro Syndrome (49,XXXXY): Case study in antenatal and postnatal from South Indian patients, an awareness to the human society." Journal of Environmental Biology 45, no. 2 (March 23, 2024): 125–29. http://dx.doi.org/10.22438/jeb/45/2/mrn-5249.
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Aim: 49, XXXXY syndrome is a rare chromosomal abnormality with an approximate incidence of 1:85000 – 1:100000. Early diagnosis is important to improve the quality of life of patient. This study was carried out to assess the chromosomal abberations in prenatal and postnatal sample of patients through cytogenetics study. Methodology: Sex chromosomal aneuplodies were performed in both amniotic fluid and peripheral venous blood samples. Cytogenetic studies such as Karyotyping was done in in-vitro culture cells by GTG banded metaphase slides. FISH test was conducted in raw sample to rule out low grade mosaicism and DNA isolated from both the samples to rule out the gain and loss of genes by Chromosomal microarray technique. Results: The two cases performed showed aneuploidy with pentasomy sex chromosomes in Karyotyping in all the metaphase analysed and FISH test resulted with five signals in sex chromosome with four copies of X chromosomes and one copy of Y chromosome in all the cells. There was no loss of genes and only gain of genes in X chromosomes as identified in Chromosomal microarray. Interpretation: Based on the findings, antenatal screening is essential and should not be avoided for any USG findings and biochemical screening. The test should not be limited only to trisomy studies. Extensive studies should be performed to rule out the genetic disorders. Chromosomal aneuploidies can be identified by cytogenetic studies like Karyotyping, FISH and Chromosomal microarray technique. Key words: Aneuploidy, Chromosomal microarray analysis, Cytogenetics, Fraccaro syndrome, Karyotyping, Pentasomy sex chromosome
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A, Lijiya, Joshy Joseph, and V. K. Govindan. "Occlusion Detection in M-FISH Human Chromosome Images." INTERNATIONAL JOURNAL OF COMPUTERS & TECHNOLOGY 13, no. 4 (April 30, 2014): 4398–404. http://dx.doi.org/10.24297/ijct.v13i4.2864.
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Automation of Chromosome Analysis has long been considered a tedious task due to the partial occlusion of chromosomes. This calls for a non-trivial, dedicated procedure to segment chromosomes. In this paper, a new method is proposed which detects and separates occluded chromosomes, by separating out the chromosome cluster from the M-FISH image, followed by detecting the cut-points along which these clusters can be split into multiple regions. These regions are then combined into separate partial chromosomes based on difference matrix. After this stage the invisible regions due to occlusion is reconstructed based on the visibility in the five channels. The performance of the new proposal  was compared with the existing work and observed better performance in resolving occlusions. With 15 occluded chromosome images tested, 90% accuracy was obtained
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Marshall Graves, Jennifer A., and Iole Barbieri. "Chromosome segregation from cell hybrids. VII. Reverse segregation from karyoplast hybrids suggests control by cytoplasmic factors." Genome 35, no. 3 (June 1, 1992): 537–40. http://dx.doi.org/10.1139/g92-079.
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Using human and Chinese hamster established lines as cell parents, we constructed hamster–human cell hybrids and human cell – hamster karyoplast hybrids. The cell hybrids retained one or two sets of hamster chromosomes and lost most of the human chromosomes. The karyoplast hybrids, however, retained a full set of human chromosomes and lost most of the Chinese hamster chromosomes. This reverse segregation pattern implies that cytoplasmic factors are major determinants of the direction of chromosome segregation.Key words: cell hybrids, chromosome loss, cytoplasmic factors, reverse segregation.
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Lo, Anthony W. I., Carl N. Sprung, Bijan Fouladi, Mehrdad Pedram, Laure Sabatier, Michelle Ricoul, Gloria E. Reynolds, and John P. Murnane. "Chromosome Instability as a Result of Double-Strand Breaks near Telomeres in Mouse Embryonic Stem Cells." Molecular and Cellular Biology 22, no. 13 (July 1, 2002): 4836–50. http://dx.doi.org/10.1128/mcb.22.13.4836-4850.2002.
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ABSTRACT Telomeres are essential for protecting the ends of chromosomes and preventing chromosome fusion. Telomere loss has been proposed to play an important role in the chromosomal rearrangements associated with tumorigenesis. To determine the relationship between telomere loss and chromosome instability in mammalian cells, we investigated the events resulting from the introduction of a double-strand break near a telomere with I-SceI endonuclease in mouse embryonic stem cells. The inactivation of a selectable marker gene adjacent to a telomere as a result of the I-SceI-induced double-strand break involved either the addition of a telomere at the site of the break or the formation of inverted repeats and large tandem duplications on the end of the chromosome. Nucleotide sequence analysis demonstrated large deletions and little or no complementarity at the recombination sites involved in the formation of the inverted repeats. The formation of inverted repeats was followed by a period of chromosome instability, characterized by amplification of the subtelomeric region, translocation of chromosomal fragments onto the end of the chromosome, and the formation of dicentric chromosomes. Despite this heterogeneity, the rearranged chromosomes eventually acquired telomeres and were stable in most of the cells in the population at the time of analysis. Our observations are consistent with a model in which broken chromosomes that do not regain a telomere undergo sister chromatid fusion involving nonhomologous end joining. Sister chromatid fusion is followed by chromosome instability resulting from breakage-fusion-bridge cycles involving the sister chromatids and rearrangements with other chromosomes. This process results in highly rearranged chromosomes that eventually become stable through the addition of a telomere onto the broken end. We have observed similar events after spontaneous telomere loss in a human tumor cell line, suggesting that chromosome instability resulting from telomere loss plays a role in chromosomal rearrangements associated with tumor cell progression.
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Arkesteijn, GJ, AC Martens, and A. Hagenbeek. "Bivariate flow karyotyping in human Philadelphia-positive chronic myelocytic leukemia." Blood 72, no. 1 (July 1, 1988): 282–86. http://dx.doi.org/10.1182/blood.v72.1.282.282.
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Abstract Chromosome analysis on clinical leukemia material was done by means of flow cytometry (flow karyotyping) to investigate the applicability of this technique in the detection of leukemia-associated abnormalities. Flow karyotyping was performed on blood or bone marrow samples from eight patients with chronic myelocytic leukemia (CML) after a culture period of four days and arresting the cells in metaphase during the last 16 hours. Discontinuous density gradient centrifugation proved to be essential in removing debris and dead cells from the cell suspensions. By this procedure the mitotic index increase ranged from 2 to 80 times initial values. Chromosomes were isolated and stained with two base pair-specific fluorochromes, ie, chromomycin A3 and Hoechst 33258, and run through a specially designed dual-laser beam flow cytometer. Generally, 20,000 chromosomes or more were measured. The data were computer stored in list mode. Besides the clear detection of the specific Philadelphia chromosome, trisomies and other additional chromosomal aberrations [like an i(17q)] were visualized. Quantitative analysis revealed the percentage of subclones containing a certain chromosomal anomaly. Conventional cytogenetic analysis confirmed these findings. In seven of eight cases, CML could be diagnosed on the basis of the presence of a Philadelphia chromosome in the flow karyogram. In one of these seven, the conventional cytogenetic analysis was unknown at that time. The remaining six all matched the standard cytogenetics. The one failure out of eight could be attributed to the specific stimulating conditions in the culture. Although it is impossible by this technique to determine the position of the breakpoint, the involved chromosomes in the translocation event could be identified. In some cases, low percentages of aberrations could not be detected. This study shows that CML can be diagnosed on the basis of flow karyotypic results. Additional chromosomal aberrations can be detected provided that changes in the amount of DNA per chromosome have occurred. Exact quantification of the composition of subclones in the case of mosaicism appear difficult.
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Arkesteijn, GJ, AC Martens, and A. Hagenbeek. "Bivariate flow karyotyping in human Philadelphia-positive chronic myelocytic leukemia." Blood 72, no. 1 (July 1, 1988): 282–86. http://dx.doi.org/10.1182/blood.v72.1.282.bloodjournal721282.
Full textAbstract:
Chromosome analysis on clinical leukemia material was done by means of flow cytometry (flow karyotyping) to investigate the applicability of this technique in the detection of leukemia-associated abnormalities. Flow karyotyping was performed on blood or bone marrow samples from eight patients with chronic myelocytic leukemia (CML) after a culture period of four days and arresting the cells in metaphase during the last 16 hours. Discontinuous density gradient centrifugation proved to be essential in removing debris and dead cells from the cell suspensions. By this procedure the mitotic index increase ranged from 2 to 80 times initial values. Chromosomes were isolated and stained with two base pair-specific fluorochromes, ie, chromomycin A3 and Hoechst 33258, and run through a specially designed dual-laser beam flow cytometer. Generally, 20,000 chromosomes or more were measured. The data were computer stored in list mode. Besides the clear detection of the specific Philadelphia chromosome, trisomies and other additional chromosomal aberrations [like an i(17q)] were visualized. Quantitative analysis revealed the percentage of subclones containing a certain chromosomal anomaly. Conventional cytogenetic analysis confirmed these findings. In seven of eight cases, CML could be diagnosed on the basis of the presence of a Philadelphia chromosome in the flow karyogram. In one of these seven, the conventional cytogenetic analysis was unknown at that time. The remaining six all matched the standard cytogenetics. The one failure out of eight could be attributed to the specific stimulating conditions in the culture. Although it is impossible by this technique to determine the position of the breakpoint, the involved chromosomes in the translocation event could be identified. In some cases, low percentages of aberrations could not be detected. This study shows that CML can be diagnosed on the basis of flow karyotypic results. Additional chromosomal aberrations can be detected provided that changes in the amount of DNA per chromosome have occurred. Exact quantification of the composition of subclones in the case of mosaicism appear difficult.
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Liehr, T. "The Multicolor Fluorescence in Situ Hybridization (mFISH) Homepage." Balkan Journal of Medical Genetics 11, no. 1 (January 1, 2008): 27–32. http://dx.doi.org/10.2478/v10034-008-0014-0.
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The Multicolor Fluorescencein SituHybridization (mFISH) HomepageMulticolor fluorescencein situhybridization (mFISH) assays are essential for a precise description of chromosomal rearrangements. Routine application of such techniques on human chromosomes started in 1996 with the simultaneous use of all 24 human whole chromosome painting probes in multiplex-FISH (M-FISH) and spectral karyotyping (SKY), even though the principle of mFISH was reported in 1989. Numerous approaches for chromosomal differentiation based on mFISH assays have been established, predominantly, to characterize marker chromosomes, but also in evolutionary biology, nuclear architecture, zoology and botany. The mFISH Homepage, which reviews all available literature at http://www.med. uni-jena.de/fish/mFISH/mFISHlit.htm will be introduced here.
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Gontar, Y. V., O. Y. Verlinsky, I. E. Ilyin, and O. M. Fedota. "Investigation of human aneuploidy and polyploidy in subcidiary reproductive technology programs." Visnik ukrains'kogo tovaristva genetikiv i selekcioneriv 14, no. 1 (June 20, 2016): 8–15. http://dx.doi.org/10.7124/visnyk.utgis.14.1.539.
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Aim. To evaluate the frequency of aneuploidy and polyploidy among sperm, preimplantation embryos, the embryos stopped in development, developing fetuses and adults studied in the framework of subsidiary reproductive technologies. Methods. To determine the chromosomes of cells from samples of different biological material cytogenetic and molecular cytogenetic methods were used. Results. The highest frequency of aneuploidy is observed among the preimplantation embryos (69.1 %) and the embryos stopped in development (60.9 %). Aneuploid/euploid chromosome set ratio is similar for both genders in all research objects except embryos stopped in development: for females it was 1:1, for males – 1.8:1. Among the spermatozoa most frequent is aneuploidy along the 18th (27 %) and sex (30.3 %) chromosomes, among preimplantation embryos – along the 13th chromosome (31.1 %), among abortuses along the 18th chromosome (40 6 %), fetuses – along the 21st chromosome (72.2 %). Sex ratio among polyploid preimplantation embryos – 1:1, among the embryos stopped in development – 2.5:1 in favor of males. Conclusions. The high frequency of aneuploidy among the early embryos is a leading cause of implantation failure, spontaneous abortion at different timing or the presence of multiple fetal malformations. Preimplantation genetic screening is essential for reducing the incidence of chromosomal abnormalities and increase in the effectiveness of subsidiary reproductive technologies.Keywords: chromosomal abnormalities, aneuploidy, polyploidy, karyotype, preimplantation genetic screening.
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Nagele, R. G., T. Freeman, L. McMorrow, Z. Thomson, K. Kitson-Wind, and Hy Lee. "Chromosomes exhibit preferential positioning in nuclei of quiescent human cells." Journal of Cell Science 112, no. 4 (February 15, 1999): 525–35. http://dx.doi.org/10.1242/jcs.112.4.525.
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The relative spatial positioning of chromosomes 7, 8, 16, X and Y was examined in nuclei of quiescent (noncycling) diploid and triploid human fibroblasts using fluorescence in situ hybridization (FISH) with chromosome-specific DNA probes and digital imaging. In quiescent diploid cells, interhomolog distances and chromosome homolog position maps revealed a nonrandom, preferential topology for chromosomes 7, 8 and 16, whereas chromosome X approximated a more random distribution. Variations in the orientation of nuclei on the culture substratum tended to hinder detection of an ordered chromosome topology at interphase by biasing homolog position maps towards random distributions. Using two chromosome X homologs as reference points in triploid cells (karyotype = 69, XXY), the intranuclear location of chromosome Y was found to be predictable within remarkably narrow spatial limits. Dual-FISH with various combinations of chromosome-specific DNA probes and contrasting fluorochromes was used to identify adjacent chromosomes in mitotic rosettes and test whether they are similarly positioned in interphase nuclei. From among the combinations tested, chromosomes 8 and 11 were found to be closely apposed in most mitotic rosettes and interphase nuclei. Overall, results suggest the existence of an ordered interphase chromosome topology in quiescent human cells in which at least some chromosome homologs exhibit a preferred relative intranuclear location that may correspond to the observed spatial order of chromosomes in rosettes of mitotic cells.
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Hall, Judith G. "How imprinting is relevant to human disease." Development 108, Supplement (April 1, 1990): 141–48. http://dx.doi.org/10.1242/dev.108.supplement.141.
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Genomic imprinting appears to be a ubiquitous process in mammals involving many chromosome segments whose affects are dependent on their parental origin. One of the challenges for clinical geneticists is to determine which disorders are manifesting imprinting effects and which families are affected. Re-evaluation of cases of chromosomal abnormalities and family histories of disease manifestations should give important clues. Examination of the regions of human chromosomes homologous to mouse imprinted chromosomal regions may yield useful information. Cases of discordance in monozygous twins may also provide important insights into imprinted modification of diseases.
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Iourov, Ivan Y., Ilia V. Soloviev, Svetlana G. Vorsanova, Viktor V. Monakhov, and Yuri B. Yurov. "An Approach for Quantitative Assessment of Fluorescence In Situ Hybridization (FISH) Signals for Applied Human Molecular Cytogenetics." Journal of Histochemistry & Cytochemistry 53, no. 3 (March 2005): 401–8. http://dx.doi.org/10.1369/jhc.4a6419.2005.
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A number of applied molecular cytogenetic studies require the quantitative assessment of fluorescence in situ hybridization (FISH) signals (for example, interphase FISH analysis of aneuploidy by chromosome enumeration DNA probes; analysis of somatic pairing of homologous chromosomes in interphase nuclei; identification of chromosomal heteromorphism after FISH with satellite DNA probes for differentiation of parental origin of homologous chromosome, etc.). We have performed a pilot study to develop a simple technique for quantitative assessment of FISH signals by means of the digital capturing of microscopic images and the intensity measuring of hybridization signals using Scion Image software, commonly used for quantification of electrophoresis gels. We have tested this approach by quantitative analysis of FISH signals after application of chromosome-specific DNA probes for aneuploidy scoring in interphase nuclei in cells of different human tissues. This approach allowed us to exclude or confirm a low-level mosaic form of aneuploidy by quantification of FISH signals (for example, discrimination of pseudo-monosomy and artifact signals due to over-position of hybridization signals). Quantification of FISH signals was also used for analysis of somatic pairing of homologous chromosomes in nuclei of postmortem brain tissues after FISH with “classical” satellite DNA probes for chromosomes 1, 9, and 16. This approach has shown a relatively high efficiency for the quantitative registration of chromosomal heteromorphism due to variations of centromeric alphoid DNA in homologous parental chromosomes. We propose this approach to be efficient and to be considered as a useful tool in addition to visual FISH signal analysis for applied molecular cytogenetic studies.
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Sanchez, Laura, Paulino Martínez, and Vicente Goyanes. "Analysis of centromere size in human chromosomes 1, 9, 15, and 16 by electron microscopy." Genome 34, no. 5 (October 1, 1991): 710–13. http://dx.doi.org/10.1139/g91-109.
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Human chromosomes were treated with 5-azacytidine and analyzed by whole-mount electron microscopy. This base analogue produces undercondensation of heterochromatin and separation of the centromere from the bulk of pericentromeric heterochromatin in chromosomes 1, 9, 15, and 16, which allows clear delimitation of the centromere regions. A quantitative analysis of centromeres showed that chromosomes 1, 9, and 16 have centromeres of different size. The centromere of chromosome 15 is similar in size to that of chromosome 9 and different from those of chromosomes 1 and 16. No interindividual variation for centromere size was found. A positive correlation between centromere and chromosome size was found for the chromosomes analyzed.Key words: centromere size, human chromosomes, electron microscopy.
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Morris, SW, MB Valentine, DN Shapiro, JE Sublett, LL Deaven, JT Foust, WM Roberts, DP Cerretti, and AT Look. "Reassignment of the human CSF1 gene to chromosome 1p13-p21." Blood 78, no. 8 (October 15, 1991): 2013–20. http://dx.doi.org/10.1182/blood.v78.8.2013.2013.
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Abstract Human macrophage colony-stimulating factor (CSF-1 or M-CSF) is encoded by a single gene that was previously assigned to the long arm of chromosome 5, band q33.1, in a region adjacent to the gene encoding its receptor (Pettenati MJ, et al, Proc Natl Acad Sci USA 84:2970, 1987). Using fluorescence in situ hybridization with genomic probes to examine normal metaphase chromosomes, we reassigned the human CSF1 gene to the short arm of chromosome 1, bands p13-p21. We confirmed this result by hybridizing a CSF1 cDNA probe to filters containing flow-sorted chromosomes and by identifying CSF1 sequences in DNAs extracted from human x rodent somatic cell hybrids that contained human chromosome 1 but not human chromosome 5. Our findings are consistent with studies that have shown tight linkage between the murine CSF1 and amylase genes, as part of a conserved linkage group between mouse chromosome 3 and the short arm of human chromosome 1, which also includes the genes encoding the beta subunits of thyrotropin and nerve growth factor. Assignment of the CSF1 gene to chromosome 1 at bands p13-p21 raises the possibility that it may be altered by certain nonrandom chromosomal abnormalities arising in human hematopoietic malignancies and solid tumors.
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Morris, SW, MB Valentine, DN Shapiro, JE Sublett, LL Deaven, JT Foust, WM Roberts, DP Cerretti, and AT Look. "Reassignment of the human CSF1 gene to chromosome 1p13-p21." Blood 78, no. 8 (October 15, 1991): 2013–20. http://dx.doi.org/10.1182/blood.v78.8.2013.bloodjournal7882013.
Full textAbstract:
Human macrophage colony-stimulating factor (CSF-1 or M-CSF) is encoded by a single gene that was previously assigned to the long arm of chromosome 5, band q33.1, in a region adjacent to the gene encoding its receptor (Pettenati MJ, et al, Proc Natl Acad Sci USA 84:2970, 1987). Using fluorescence in situ hybridization with genomic probes to examine normal metaphase chromosomes, we reassigned the human CSF1 gene to the short arm of chromosome 1, bands p13-p21. We confirmed this result by hybridizing a CSF1 cDNA probe to filters containing flow-sorted chromosomes and by identifying CSF1 sequences in DNAs extracted from human x rodent somatic cell hybrids that contained human chromosome 1 but not human chromosome 5. Our findings are consistent with studies that have shown tight linkage between the murine CSF1 and amylase genes, as part of a conserved linkage group between mouse chromosome 3 and the short arm of human chromosome 1, which also includes the genes encoding the beta subunits of thyrotropin and nerve growth factor. Assignment of the CSF1 gene to chromosome 1 at bands p13-p21 raises the possibility that it may be altered by certain nonrandom chromosomal abnormalities arising in human hematopoietic malignancies and solid tumors.
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Wakchaure, Sakshi. "Chromosome Classification Using Deep Learning Technique." International Journal for Research in Applied Science and Engineering Technology 11, no. 5 (May 31, 2023): 4195–202. http://dx.doi.org/10.22214/ijraset.2023.52479.
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Abstract: Automated chromosome classification is a critical task in cytogenetics and has been traditionally performed manually. Recent advancements in image processing and machine learning have opened new avenues for automated chromosome classification. This paper presents a novel method for straightening and classifying chromosomes, utilizing a blend of imageprocessing techniques and a convolutional neural network (CNN) algorithm. The proposed approach involves pre-processing chromosome images, which includes straightening them to eliminate any curvature caused by their natural shape and extracting features with the aid of a CNN. The design of the method allows for the training and testing of images, facilitating the prediction of chromosomal abnormalities with high accuracy. The performance of the method was evaluated using a dataset of chromosome images, demonstrating exceptional accuracy and robustness. The proposed approach was evaluated using publicly available datasets of human chromosomes and achieved an accuracy of 93% without the straightening of chromosomes and 96% after the straightening of chromosomes. This method has the potential to be applied in cytogenetics and medical diagnosis, where precise and efficient chromosome classification is vital, and the ability to straighten chromosomes can enhance the accuracy of the analysis.
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Machado, Cristina, Claudio E. Sunkel, and Deborah J. Andrew. "Human Autoantibodies Reveal Titin as a Chromosomal Protein." Journal of Cell Biology 141, no. 2 (April 20, 1998): 321–33. http://dx.doi.org/10.1083/jcb.141.2.321.
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Assembly of the higher-order structure of mitotic chromosomes is a prerequisite for proper chromosome condensation, segregation and integrity. Understanding the details of this process has been limited because very few proteins involved in the assembly of chromosome structure have been discovered. Using a human autoimmune scleroderma serum that identifies a chromosomal protein in human cells and Drosophila embryos, we cloned the corresponding Drosophila gene that encodes the homologue of vertebrate titin based on protein size, sequence similarity, developmental expression and subcellular localization. Titin is a giant sarcomeric protein responsible for the elasticity of striated muscle that may also function as a molecular scaffold for myofibrillar assembly. Molecular analysis and immunostaining with antibodies to multiple titin epitopes indicates that the chromosomal and muscle forms of titin may vary in their NH2 termini. The identification of titin as a chromosomal component provides a molecular basis for chromosome structure and elasticity.
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Mahmoud Hamza, Asma, and Sumaya Hussein Elboshra. "Mitotic metaphase karyotype of the mosquito Anopheles arabiensis Patton (Diptera: Culicidae) from Kassala State, eastern Sudan." Caryologia 76, no. 2 (December 31, 2023): 15–21. http://dx.doi.org/10.36253/caryologia-2095.
Full textAbstract:
The mosquito Anopheles arabiensis Patton is the most important malaria vector in Sudan. The study was conducted for the first time to describe numerically the karyotype of An. arabiensis from Kassala State, eastern Sudan. Adults An. arabiensis were caught from human dwellings during the rainy season of 2022. We examined for the first time the utility of brain ganglia tissues of adult mosquitoes for mitotic chromosomal preparations using Giemsa stain - spreading technique. High-quality chromosomal preparations were examined and photographed. Chromosome measurements were carried out using computer software and analyzed statistically using SPSS® software. The diploid mitotic chromosome complement of An. arabiensis consists of three pairs of chromosomes, two pairs of metacentric autosomes (chromosome II and chromosome III) and one acrocentric dot-shaped pair, sex chromosome, which is homomorphic in females (XX) and heteromorphic in males (XY). Chromosome II was described as the longest (2.61±0.07) of the complement and constitute 44.39% of the total length (5.88 μm) of the haploid chromosomes set, while chromosome I (X=1.39 ±0.04; Y=1.04±0.04) as the shortest chromosome. Chromosome X appears in the males significantly larger than chromosome Y (P = 0.00). Chromosome III has an intermediate length (1.88±0.06) compared with the other chromosomes. Comparison of the average lengths of the three chromosome pairs by ANOVA test revealed highly statistical significant differences between them (P < 0.00). The study establishes a strong cytogentic data, which can contribute to accurate identification of the mosquito An. arabiensis and to planning human malaria vector control programs in Kassala State, eastern Sudan.
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Babu, Arvind, and Ram S. Verma. "Characterization of human chromosomal constitutive heterochromatin." Canadian Journal of Genetics and Cytology 28, no. 5 (October 1, 1986): 631–44. http://dx.doi.org/10.1139/g86-093.
Full textAbstract:
The constitutive heterochromatin of human chromosomes is evaluated by various selective staining techniques, i.e., CBG, G-11, distamycin A plus 4,6-diamidino-2-phenylindole-2-HCl (DA/DAPI), the fluorochrome D287/170, and Giemsa staining following the treatments with restriction endonucleases AluI and HaeIII. It is suggested that the constitutive heterochromatin could be arbitrarily divided into at least seven types depending on the staining profiles expressed by different regions of C-bands. The pericentromeric C-bands of chromosomes 1, 5, 7, 9, 13–18, and 20–22 consist of more than one type of chromatin, of which chromosome 1 presents the highest degree of heterogeneity. Chromosomes 3 and 4 show relatively less consistent heterogeneous fractions in their C-bands. The C-bands of chromosomes 10, 19, and the Y do not have much heterogeneity but have characteristic patterns with other methods using restriction endonucleases. Chromosomes 2, 6, 8, 11, 12, and X have homogeneous bands stained by the CBG technique only. Among the chromosomes with smaller pericentric C-bands, chromosome 18 shows frequent heteromorphic variants for the size and position (inversions) of the AluI resistant fraction of C-band. The analysis of various types of heterochromatin with respect to specific satellite and nonsatellite DNA sequences suggest that the staining profiles are probably related to sequence diversity.Key words: polymorphism, heteromorphism, heterogeneity, banding, restriction endonucleases.
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Milioto, Vanessa, Luca Sineo, and Francesca Dumas. "Chromosome Painting in Cercopithecus petaurista (Schreber, 1774) Compared to Other Monkeys of the Cercopithecini Tribe (Catarrhini, Primates)." Life 13, no. 5 (May 17, 2023): 1203. http://dx.doi.org/10.3390/life13051203.
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The Cercopithecini tribe includes terrestrial and arboreal clades whose relationships are controversial, with a high level of chromosome rearrangements. In order to provide new insights on the tribe’s phylogeny, chromosome painting, using the complete set of human syntenic probes, was performed in Cercopithecus petaurista, a representative species of the Cercopithecini tribe. The results show C. petaurista with a highly rearranged karyotype characterized by the fission of human chromosomes 1, 2, 3, 5, 6, 8, 11, and 12. These results compared with the literature data permit us to confirm the monophyly of the Cercopithecini tribe (fissions of chromosomes 5 and 6), as previously proposed by chromosomal and molecular data. Furthermore, we support the monophyly of the strictly arboreal Cercopithecus clade, previously proposed by the molecular approach, identifying chromosomal synapomorphies (fissions of chromosomes 1, 2, 3, 11, 12). We also add additional markers that can be useful for deciphering arboreal Cercopithecini phylogeny. For example, the fission of chromosome 8 is synapomorphy linking C. petaurista, C. erythrogaster, and C. nictitans among the arboreal species. Finally, a telomeric sequence probe was mapped on C. petaurista, showing only classic telomeric signals and giving no support to a previous hypothesis regarding a link between interspersed telomeric sequences in high rearranged genomes.
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Croft, Jenny A., Joanna M. Bridger, Shelagh Boyle, Paul Perry, Peter Teague, and Wendy A. Bickmore. "Differences in the Localization and Morphology of Chromosomes in the Human Nucleus." Journal of Cell Biology 145, no. 6 (June 14, 1999): 1119–31. http://dx.doi.org/10.1083/jcb.145.6.1119.
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Using fluorescence in situ hybridization we show striking differences in nuclear position, chromosome morphology, and interactions with nuclear substructure for human chromosomes 18 and 19. Human chromosome 19 is shown to adopt a more internal position in the nucleus than chromosome 18 and to be more extensively associated with the nuclear matrix. The more peripheral localization of chromosome 18 is established early in the cell cycle and is maintained thereafter. We show that the preferential localization of chromosomes 18 and 19 in the nucleus is reflected in the orientation of translocation chromosomes in the nucleus. Lastly, we show that the inhibition of transcription can have gross, but reversible, effects on chromosome architecture. Our data demonstrate that the distribution of genomic sequences between chromosomes has implications for nuclear structure and we discuss our findings in relation to a model of the human nucleus that is functionally compartmentalized.
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Nakayama, Tomohiro, Satoshi Asai, Yasuo Takahashi, Oto Maekawa, and Yasuji Kasama. "Overlapping of Genes in the Human Genome." International Journal of Biomedical Science 3, no. 1 (March 15, 2007): 14–19. http://dx.doi.org/10.59566/ijbs.2007.3014.
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Overlapping genes are relatively common in DNA and rNA viruses. there are several examples in bac-terial and eukaryotic genomes, but, in general, overlapping genes are quite rare in organisms other than viruses. there have been a few reports of overlapping genes in mammalian genomes. the present study identified all of the overlapping loci and overlapping exons in every chromosome of the human genome using a public database. the total number of overlapping loci on the same and opposite strands was 949 and 743, respectively. similarly, in every chromosome, the instances in which two loci were located on the same strand were similar to the number of 2 genes observed on opposite strands, except for chromosome 5. the number of 2 exons located on the same strand was higher than that for 2 exons located on opposite strands, indicating the presence of many comprehensive-type overlaps. the mean percentage of overlapping exons on opposite strands in each chromosome was 3.3%, suggesting that parts of the nucleotide sequences of 26,501 exons are used to produce 2 transcribed products from each strand. the ratio of the number of overlapping regions to chromosomal length revealed that, on chromosomes 22, 17 and 19, ratios were high for both types of 2 loci, with exons located on the same and opposite strands. ratios were low on chromosomes Y, 13 and 18. these results show that all overlapping types are distributed throughout the human genome, but that distributions differ for each chromosome.
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Thévenin, Annelyse, Liat Ein-Dor, Michal Ozery-Flato, and Ron Shamir. "Functional gene groups are concentrated within chromosomes, among chromosomes and in the nuclear space of the human genome." Nucleic Acids Research 42, no. 15 (July 23, 2014): 9854–61. http://dx.doi.org/10.1093/nar/gku667.
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Abstract Genomes undergo changes in organization as a result of gene duplications, chromosomal rearrangements and local mutations, among other mechanisms. In contrast to prokaryotes, in which genes of a common function are often organized in operons and reside contiguously along the genome, most eukaryotes show much weaker clustering of genes by function, except for few concrete functional groups. We set out to check systematically if there is a relation between gene function and gene organization in the human genome. We test this question for three types of functional groups: pairs of interacting proteins, complexes and pathways. We find a significant concentration of functional groups both in terms of their distance within the same chromosome and in terms of their dispersal over several chromosomes. Moreover, using Hi-C contact map of the tendency of chromosomal segments to appear close in the 3D space of the nucleus, we show that members of the same functional group that reside on distinct chromosomes tend to co-localize in space. The result holds for all three types of functional groups that we tested. Hence, the human genome shows substantial concentration of functional groups within chromosomes and across chromosomes in space.
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Sekhar, Vandana, Shawna C. Reed, and Alison A. McBride. "Interaction of the Betapapillomavirus E2 Tethering Protein with Mitotic Chromosomes." Journal of Virology 84, no. 1 (October 21, 2009): 543–57. http://dx.doi.org/10.1128/jvi.01908-09.
Full textAbstract:
ABSTRACT During persistent papillomavirus infection, the viral E2 protein tethers the viral genome to the host cell chromosomes, ensuring maintenance and segregation of the viral genome during cell division. However, E2 proteins from different papillomaviruses interact with distinct chromosomal regions and targets. The tethering mechanism has been best characterized for bovine papillomavirus type 1 (BPV1), where the E2 protein tethers the viral genome to mitotic chromosomes in complex with the cellular bromodomain protein, Brd4. In contrast, the betapapillomavirus human papillomavirus type 8 (HPV8) E2 protein binds to the repeated ribosomal DNA genes that are found on the short arm of human acrocentric chromosomes. In this study, we show that a short 16-amino-acid peptide from the hinge region and the C-terminal DNA binding domain of HPV8 E2 are necessary and sufficient for interaction with mitotic chromosomes. This 16-amino-acid region contains an RXXS motif that is highly conserved among betapapillomaviruses, and both arginine 250 and serine 253 residues within this motif are required for mitotic chromosome binding. The HPV8 E2 proteins are highly phosphorylated, and serine 253 is a site of phosphorylation. The HPV8 E2 chromosome binding sequence also has sequence similarity with chromosome binding regions in the gammaherpesvirus EBNA and LANA tethering proteins.