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Deborah A Dawson - One of the best experts on this subject based on the ideXlab platform.
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gene order and recombination rate in Homologous Chromosome regions of the chicken and a passerine bird
Molecular Biology and Evolution, 2007Co-Authors: Mikael Akesson, Deborah A Dawson, Terry Burke, Josephine M. PembertonAbstract:Genome structure has been found to be highly conserved between distantly related birds and recent data for a limited part of the genome suggest that this is true also for the gene order (synteny) within Chromosomes. Here, we confirm that synteny is maintained for large chromosomal regions in chicken and a passerine bird, the great reed warbler Acrocephalus arundinaceus, with few rearrangements, but in contrast show that the recombination-based linkage map distances differ substantially between these species. We assigned a chromosomal location based on sequence similarity to the chicken genome sequence to a set of inicrosatellite loci mapped in a pedigree of great reed warblers. We detected Homologous loci on 14 different Chromosomes corresponding to chicken Chromosomes Gga1-5, 7-9, 13, 19, 20, 24, 25, and Z. It is known that 2 passerine macroChromosomes correspond to the chicken Chromosome Gga1. Homology of 2 different great reed warbler linkage groups (LG13 and LG5) to Gga1 allowed us to locate the split to a position between 20.8 and 84.8 Mb on Gga1. Data from the 5 chromosomal regions (on Gga1, 2, 3, 5, and Z) with 3 or more Homologous loci showed that synteny was conserved with the exception of 2 large previously unreported inversions on Gga1/LG5 and Gga2/LG3, respectively. Recombination data from the 9 chromosomal regions in which we identified 2 or more Homologous loci (accounting for the inversions) showed that the linkage map distances in great reed warblers were only 6.3% and 13.3% of those in chickens for males and females, respectively. This is likely to reflect the true interspecific difference in recombination rate because our markers were not located in potentially low-recombining regions: several linkage groups covered a substantial part of their corresponding chicken Chromosomes and were not restricted to centromeres. We conclude that recombination rates may differ strongly between bird species with highly conserved genome structure and synteny and that the chicken linkage map may not be suitable, in terms of genetic distances, as a model for all bird species. (Less)
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gene order and recombination rate in Homologous Chromosome regions of the chicken and a passerine bird
Molecular Biology and Evolution, 2007Co-Authors: Mikael Akesson, Deborah A Dawson, Terry Burke, Josephine M. PembertonAbstract:Genome structure has been found to be highly conserved between distantly related birds and recent data for a limited part of the genome suggest that this is true also for the gene order (synteny) within Chromosomes. Here, we confirm that synteny is maintained for large chromosomal regions in chicken and a passerine bird, the great reed warbler Acrocephalus arundinaceus, with few rearrangements, but in contrast show that the recombination-based linkage map distances differ substantially between these species. We assigned a chromosomal location based on sequence similarity to the chicken genome sequence to a set of microsatellite loci mapped in a pedigree of great reed warblers. We detected Homologous loci on 14 different Chromosomes corresponding to chicken Chromosomes Gga1-5, 7-9, 13, 19, 20, 24, 25, and Z. It is known that 2 passerine macroChromosomes correspond to the chicken Chromosome Gga1. Homology of 2 different great reed warbler linkage groups (LG13 and LG5) to Gga1 allowed us to locate the split to a position between 20.8 and 84.8 Mb on Gga1. Data from the 5 chromosomal regions (on Gga1, 2, 3, 5, and Z) with 3 or more Homologous loci showed that synteny was conserved with the exception of 2 large previously unreported inversions on Gga1/LG5 and Gga2/LG3, respectively. Recombination data from the 9 chromosomal regions in which we identified 2 or more Homologous loci (accounting for the inversions) showed that the linkage map distances in great reed warblers were only 6.3% and 13.3% of those in chickens for males and females, respectively. This is likely to reflect the true interspecific difference in recombination rate because our markers were not located in potentially low-recombining regions: several linkage groups covered a substantial part of their corresponding chicken Chromosomes and were not restricted to centromeres. We conclude that recombination rates may differ strongly between bird species with highly conserved genome structure and synteny and that the chicken linkage map may not be suitable, in terms of genetic distances, as a model for all bird species.
Josephine M. Pemberton - One of the best experts on this subject based on the ideXlab platform.
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gene order and recombination rate in Homologous Chromosome regions of the chicken and a passerine bird
Molecular Biology and Evolution, 2007Co-Authors: Mikael Akesson, Deborah A Dawson, Terry Burke, Josephine M. PembertonAbstract:Genome structure has been found to be highly conserved between distantly related birds and recent data for a limited part of the genome suggest that this is true also for the gene order (synteny) within Chromosomes. Here, we confirm that synteny is maintained for large chromosomal regions in chicken and a passerine bird, the great reed warbler Acrocephalus arundinaceus, with few rearrangements, but in contrast show that the recombination-based linkage map distances differ substantially between these species. We assigned a chromosomal location based on sequence similarity to the chicken genome sequence to a set of inicrosatellite loci mapped in a pedigree of great reed warblers. We detected Homologous loci on 14 different Chromosomes corresponding to chicken Chromosomes Gga1-5, 7-9, 13, 19, 20, 24, 25, and Z. It is known that 2 passerine macroChromosomes correspond to the chicken Chromosome Gga1. Homology of 2 different great reed warbler linkage groups (LG13 and LG5) to Gga1 allowed us to locate the split to a position between 20.8 and 84.8 Mb on Gga1. Data from the 5 chromosomal regions (on Gga1, 2, 3, 5, and Z) with 3 or more Homologous loci showed that synteny was conserved with the exception of 2 large previously unreported inversions on Gga1/LG5 and Gga2/LG3, respectively. Recombination data from the 9 chromosomal regions in which we identified 2 or more Homologous loci (accounting for the inversions) showed that the linkage map distances in great reed warblers were only 6.3% and 13.3% of those in chickens for males and females, respectively. This is likely to reflect the true interspecific difference in recombination rate because our markers were not located in potentially low-recombining regions: several linkage groups covered a substantial part of their corresponding chicken Chromosomes and were not restricted to centromeres. We conclude that recombination rates may differ strongly between bird species with highly conserved genome structure and synteny and that the chicken linkage map may not be suitable, in terms of genetic distances, as a model for all bird species. (Less)
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gene order and recombination rate in Homologous Chromosome regions of the chicken and a passerine bird
Molecular Biology and Evolution, 2007Co-Authors: Mikael Akesson, Deborah A Dawson, Terry Burke, Josephine M. PembertonAbstract:Genome structure has been found to be highly conserved between distantly related birds and recent data for a limited part of the genome suggest that this is true also for the gene order (synteny) within Chromosomes. Here, we confirm that synteny is maintained for large chromosomal regions in chicken and a passerine bird, the great reed warbler Acrocephalus arundinaceus, with few rearrangements, but in contrast show that the recombination-based linkage map distances differ substantially between these species. We assigned a chromosomal location based on sequence similarity to the chicken genome sequence to a set of microsatellite loci mapped in a pedigree of great reed warblers. We detected Homologous loci on 14 different Chromosomes corresponding to chicken Chromosomes Gga1-5, 7-9, 13, 19, 20, 24, 25, and Z. It is known that 2 passerine macroChromosomes correspond to the chicken Chromosome Gga1. Homology of 2 different great reed warbler linkage groups (LG13 and LG5) to Gga1 allowed us to locate the split to a position between 20.8 and 84.8 Mb on Gga1. Data from the 5 chromosomal regions (on Gga1, 2, 3, 5, and Z) with 3 or more Homologous loci showed that synteny was conserved with the exception of 2 large previously unreported inversions on Gga1/LG5 and Gga2/LG3, respectively. Recombination data from the 9 chromosomal regions in which we identified 2 or more Homologous loci (accounting for the inversions) showed that the linkage map distances in great reed warblers were only 6.3% and 13.3% of those in chickens for males and females, respectively. This is likely to reflect the true interspecific difference in recombination rate because our markers were not located in potentially low-recombining regions: several linkage groups covered a substantial part of their corresponding chicken Chromosomes and were not restricted to centromeres. We conclude that recombination rates may differ strongly between bird species with highly conserved genome structure and synteny and that the chicken linkage map may not be suitable, in terms of genetic distances, as a model for all bird species.
Yasushi Hiraoka - One of the best experts on this subject based on the ideXlab platform.
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Phase separation drives pairing of Homologous Chromosomes
Current Genetics, 2020Co-Authors: Yasushi HiraokaAbstract:Pairing of Homologous Chromosomes is crucial for ensuring accurate segregation of Chromosomes during meiosis. Molecular mechanisms of Homologous Chromosome pairing in meiosis have been extensively studied in the fission yeast Schizosaccharomyces pombe . In this organism, meiosis-specific noncoding RNA transcribed from specific genes accumulates at the respective gene loci, and Chromosome-associated RNA–protein complexes mediate meiotic pairing of Homologous loci through phase separation. Pairing of Homologous Chromosomes also occurs in somatic diploid cells in certain situations. For example, somatic pairing of Homologous Chromosomes occurs during the early embryogenesis in diptera, and relies on the transcription-associated chromatin architecture. Earlier models also suggest that transcription factories along the Chromosome mediate pairing of Homologous Chromosomes in plants. These studies suggest that RNA bodies formed on Chromosomes mediate the pairing of Homologous Chromosomes. This review summarizes lessons from S. pombe to provide general insights into mechanisms of Homologous Chromosome pairing mediated by phase separation of Chromosome-associated RNA–protein complexes.
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A cohesin-based structural platform supporting Homologous Chromosome pairing in meiosis
Current Genetics, 2016Co-Authors: Daqiao Ding, Tokuko Haraguchi, Yasushi HiraokaAbstract:The pairing and recombination of Homologous Chromosomes during the meiotic prophase is necessary for the accurate segregation of Chromosomes in meiosis. However, the mechanism by which Homologous Chromosomes achieve this pairing has remained an open question. Meiotic cohesins have been shown to affect chromatin compaction; however, the impact of meiotic cohesins on Homologous pairing and the fine structures of cohesion-based chromatin remain to be determined. A recent report using live-cell imaging and super-resolution microscopy demonstrated that the lack of meiotic cohesins alters the Chromosome axis structures and impairs the pairing of Homologous Chromosomes. These results suggest that meiotic cohesin-based Chromosome axis structures are crucial for the pairing of Homologous Chromosomes.
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Meiotic cohesin-based Chromosome structure is essential for Homologous Chromosome pairing in Schizosaccharomyces pombe
Chromosoma, 2016Co-Authors: Daqiao Ding, Tokuko Haraguchi, Atsushi Matsuda, Kasumi Okamasa, Yuki Nagahama, Yasushi HiraokaAbstract:Chromosome structure is dramatically altered upon entering meiosis to establish chromosomal architectures necessary for the successful progression of meiosis-specific events. An early meiotic event involves the replacement of the non-SMC mitotic cohesins with their meiotic equivalents in most part of the Chromosome, forming an axis on meiotic Chromosomes. We previously demonstrated that the meiotic cohesin complex is required for Chromosome compaction during meiotic prophase in the fission yeast Schizosaccharomyces pombe . These studies revealed that Chromosomes are elongated in the absence of the meiotic cohesin subunit Rec8 and shortened in the absence of the cohesin-associated protein Pds5. In this study, using super-resolution structured illumination microscopy, we found that Rec8 forms a linear axis on Chromosomes, which is required for the organized axial structure of chromatin during meiotic prophase. In the absence of Pds5, the Rec8 axis is shortened whereas Chromosomes are widened. In rec8 or pds5 mutants, the frequency of Homologous Chromosome pairing is reduced. Thus, Rec8 and Pds5 play an essential role in building a platform to support the Chromosome architecture necessary for the spatial alignment of Homologous Chromosomes.
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dynamics of Homologous Chromosome pairing during meiotic prophase in fission yeast
Developmental Cell, 2004Co-Authors: Daqiao Ding, Ayumu Yamamoto, Tokuko Haraguchi, Yasushi HiraokaAbstract:Pairing of Homologous Chromosomes is important for Homologous recombination and correct Chromosome segregation during meiosis. It has been proposed that telomere clustering, nuclear oscillation, and recombination during meiotic prophase facilitate Homologous Chromosome pairing in fission yeast. Here we examined the contributions of these chromosomal events to Homologous Chromosome pairing, by directly observing the dynamics of chromosomal loci in living cells of fission yeast. Homologous loci exhibited a dynamic process of association and dissociation during the time course of meiotic prophase. Lack of nuclear oscillation reduced association frequency for both centromeric and arm regions of the Chromosome. Lack of telomere clustering or recombination reduced association frequency at arm regions, but not significantly at centromeric regions. Our results indicate that Homologous Chromosomes are spatially aligned by oscillation of telomere-bundled Chromosomes and physically linked by recombination at Chromosome arm regions; this recombination is not required for association of Homologous centromeres.
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the onset of Homologous Chromosome pairing during drosophila melanogaster embryogenesis
Journal of Cell Biology, 1993Co-Authors: Yasushi Hiraoka, Abby F. Dernburg, Susan J Parmelee, Mary C Rykowski, David A Agard, John W. SedatAbstract:We have determined the position within the nucleus of Homologous sites of the histone gene cluster in Drosophila melanogaster using in situ hybridization and high-resolution, three-dimensional wide field fluorescence microscopy. A 4.8-kb biotinylated probe for the histone gene repeat, located approximately midway along the short arm of Chromosome 2, was hybridized to whole-mount embryos in late syncytial and early cellular blastoderm stages. Our results show that the two Homologous histone loci are distinct and separate through all stages of the cell cycle up to nuclear cycle 13. By dramatic contrast, the two Homologous clusters were found to colocalize with high frequency during interphase of cycle 14. Concomitant with homolog pairing at cycle 14, both histone loci were also found to move from their position near the midline of the nucleus toward the apical side. This result suggests that coincident with the initiation of zygotic transcription, there is dramatic Chromosome and nuclear reorganization between nuclear cycles 13 and 14.
Terry Burke - One of the best experts on this subject based on the ideXlab platform.
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gene order and recombination rate in Homologous Chromosome regions of the chicken and a passerine bird
Molecular Biology and Evolution, 2007Co-Authors: Mikael Akesson, Deborah A Dawson, Terry Burke, Josephine M. PembertonAbstract:Genome structure has been found to be highly conserved between distantly related birds and recent data for a limited part of the genome suggest that this is true also for the gene order (synteny) within Chromosomes. Here, we confirm that synteny is maintained for large chromosomal regions in chicken and a passerine bird, the great reed warbler Acrocephalus arundinaceus, with few rearrangements, but in contrast show that the recombination-based linkage map distances differ substantially between these species. We assigned a chromosomal location based on sequence similarity to the chicken genome sequence to a set of inicrosatellite loci mapped in a pedigree of great reed warblers. We detected Homologous loci on 14 different Chromosomes corresponding to chicken Chromosomes Gga1-5, 7-9, 13, 19, 20, 24, 25, and Z. It is known that 2 passerine macroChromosomes correspond to the chicken Chromosome Gga1. Homology of 2 different great reed warbler linkage groups (LG13 and LG5) to Gga1 allowed us to locate the split to a position between 20.8 and 84.8 Mb on Gga1. Data from the 5 chromosomal regions (on Gga1, 2, 3, 5, and Z) with 3 or more Homologous loci showed that synteny was conserved with the exception of 2 large previously unreported inversions on Gga1/LG5 and Gga2/LG3, respectively. Recombination data from the 9 chromosomal regions in which we identified 2 or more Homologous loci (accounting for the inversions) showed that the linkage map distances in great reed warblers were only 6.3% and 13.3% of those in chickens for males and females, respectively. This is likely to reflect the true interspecific difference in recombination rate because our markers were not located in potentially low-recombining regions: several linkage groups covered a substantial part of their corresponding chicken Chromosomes and were not restricted to centromeres. We conclude that recombination rates may differ strongly between bird species with highly conserved genome structure and synteny and that the chicken linkage map may not be suitable, in terms of genetic distances, as a model for all bird species. (Less)
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gene order and recombination rate in Homologous Chromosome regions of the chicken and a passerine bird
Molecular Biology and Evolution, 2007Co-Authors: Mikael Akesson, Deborah A Dawson, Terry Burke, Josephine M. PembertonAbstract:Genome structure has been found to be highly conserved between distantly related birds and recent data for a limited part of the genome suggest that this is true also for the gene order (synteny) within Chromosomes. Here, we confirm that synteny is maintained for large chromosomal regions in chicken and a passerine bird, the great reed warbler Acrocephalus arundinaceus, with few rearrangements, but in contrast show that the recombination-based linkage map distances differ substantially between these species. We assigned a chromosomal location based on sequence similarity to the chicken genome sequence to a set of microsatellite loci mapped in a pedigree of great reed warblers. We detected Homologous loci on 14 different Chromosomes corresponding to chicken Chromosomes Gga1-5, 7-9, 13, 19, 20, 24, 25, and Z. It is known that 2 passerine macroChromosomes correspond to the chicken Chromosome Gga1. Homology of 2 different great reed warbler linkage groups (LG13 and LG5) to Gga1 allowed us to locate the split to a position between 20.8 and 84.8 Mb on Gga1. Data from the 5 chromosomal regions (on Gga1, 2, 3, 5, and Z) with 3 or more Homologous loci showed that synteny was conserved with the exception of 2 large previously unreported inversions on Gga1/LG5 and Gga2/LG3, respectively. Recombination data from the 9 chromosomal regions in which we identified 2 or more Homologous loci (accounting for the inversions) showed that the linkage map distances in great reed warblers were only 6.3% and 13.3% of those in chickens for males and females, respectively. This is likely to reflect the true interspecific difference in recombination rate because our markers were not located in potentially low-recombining regions: several linkage groups covered a substantial part of their corresponding chicken Chromosomes and were not restricted to centromeres. We conclude that recombination rates may differ strongly between bird species with highly conserved genome structure and synteny and that the chicken linkage map may not be suitable, in terms of genetic distances, as a model for all bird species.
Mikael Akesson - One of the best experts on this subject based on the ideXlab platform.
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gene order and recombination rate in Homologous Chromosome regions of the chicken and a passerine bird
Molecular Biology and Evolution, 2007Co-Authors: Mikael Akesson, Deborah A Dawson, Terry Burke, Josephine M. PembertonAbstract:Genome structure has been found to be highly conserved between distantly related birds and recent data for a limited part of the genome suggest that this is true also for the gene order (synteny) within Chromosomes. Here, we confirm that synteny is maintained for large chromosomal regions in chicken and a passerine bird, the great reed warbler Acrocephalus arundinaceus, with few rearrangements, but in contrast show that the recombination-based linkage map distances differ substantially between these species. We assigned a chromosomal location based on sequence similarity to the chicken genome sequence to a set of inicrosatellite loci mapped in a pedigree of great reed warblers. We detected Homologous loci on 14 different Chromosomes corresponding to chicken Chromosomes Gga1-5, 7-9, 13, 19, 20, 24, 25, and Z. It is known that 2 passerine macroChromosomes correspond to the chicken Chromosome Gga1. Homology of 2 different great reed warbler linkage groups (LG13 and LG5) to Gga1 allowed us to locate the split to a position between 20.8 and 84.8 Mb on Gga1. Data from the 5 chromosomal regions (on Gga1, 2, 3, 5, and Z) with 3 or more Homologous loci showed that synteny was conserved with the exception of 2 large previously unreported inversions on Gga1/LG5 and Gga2/LG3, respectively. Recombination data from the 9 chromosomal regions in which we identified 2 or more Homologous loci (accounting for the inversions) showed that the linkage map distances in great reed warblers were only 6.3% and 13.3% of those in chickens for males and females, respectively. This is likely to reflect the true interspecific difference in recombination rate because our markers were not located in potentially low-recombining regions: several linkage groups covered a substantial part of their corresponding chicken Chromosomes and were not restricted to centromeres. We conclude that recombination rates may differ strongly between bird species with highly conserved genome structure and synteny and that the chicken linkage map may not be suitable, in terms of genetic distances, as a model for all bird species. (Less)
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gene order and recombination rate in Homologous Chromosome regions of the chicken and a passerine bird
Molecular Biology and Evolution, 2007Co-Authors: Mikael Akesson, Deborah A Dawson, Terry Burke, Josephine M. PembertonAbstract:Genome structure has been found to be highly conserved between distantly related birds and recent data for a limited part of the genome suggest that this is true also for the gene order (synteny) within Chromosomes. Here, we confirm that synteny is maintained for large chromosomal regions in chicken and a passerine bird, the great reed warbler Acrocephalus arundinaceus, with few rearrangements, but in contrast show that the recombination-based linkage map distances differ substantially between these species. We assigned a chromosomal location based on sequence similarity to the chicken genome sequence to a set of microsatellite loci mapped in a pedigree of great reed warblers. We detected Homologous loci on 14 different Chromosomes corresponding to chicken Chromosomes Gga1-5, 7-9, 13, 19, 20, 24, 25, and Z. It is known that 2 passerine macroChromosomes correspond to the chicken Chromosome Gga1. Homology of 2 different great reed warbler linkage groups (LG13 and LG5) to Gga1 allowed us to locate the split to a position between 20.8 and 84.8 Mb on Gga1. Data from the 5 chromosomal regions (on Gga1, 2, 3, 5, and Z) with 3 or more Homologous loci showed that synteny was conserved with the exception of 2 large previously unreported inversions on Gga1/LG5 and Gga2/LG3, respectively. Recombination data from the 9 chromosomal regions in which we identified 2 or more Homologous loci (accounting for the inversions) showed that the linkage map distances in great reed warblers were only 6.3% and 13.3% of those in chickens for males and females, respectively. This is likely to reflect the true interspecific difference in recombination rate because our markers were not located in potentially low-recombining regions: several linkage groups covered a substantial part of their corresponding chicken Chromosomes and were not restricted to centromeres. We conclude that recombination rates may differ strongly between bird species with highly conserved genome structure and synteny and that the chicken linkage map may not be suitable, in terms of genetic distances, as a model for all bird species.