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Ruth B. Phillips - One of the best experts on this subject based on the ideXlab platform.
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assignment of chinook salmon oncorhynchus tshawytscha Linkage Groups to specific chromosomes reveals a karyotype with multiple rearrangements of the chromosome arms of rainbow trout oncorhynchus mykiss
G3: Genes Genomes Genetics, 2013Co-Authors: Ruth B. Phillips, Linda K Park, Kerry A NaishAbstract:The Chinook salmon genetic Linkage Groups have been assigned to specific chromosomes using fluorescence in situ hybridization with bacterial artificial chromosome probes containing genetic markers mapped to each Linkage group in Chinook salmon and rainbow trout. Comparison of the Chinook salmon chromosome map with that of rainbow trout provides strong evidence for conservation of large syntenic blocks in these species, corresponding to entire chromosome arms in the rainbow trout as expected. In almost every case, the markers were found at approximately the same location on the chromosome arm in each species, suggesting conservation of marker order on the chromosome arms of the two species in most cases. Although theoretically a few centric fissions could convert the karyotype of rainbow trout (2N = 58–64) into that of Chinook salmon (2N = 68) or vice versa, our data suggest that chromosome arms underwent multiple centric fissions and subsequent new centric fusions to form the current karyotypes. The morphology of only approximately one-third of the chromosome pairs have been conserved between the two species.
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assignment of atlantic salmon salmo salar Linkage Groups to specific chromosomes conservation of large syntenic blocks corresponding to whole chromosome arms in rainbow trout oncorhynchus mykiss
BMC Genetics, 2009Co-Authors: Roy G Danzmann, Ruth B. Phillips, Kimberly A. Keatley, Matthew R. Morasch, Abigail B. Ventura, Krzysztof P. Lubieniecki, Ben F. Koop, William S. DavidsonAbstract:Most teleost species, especially freshwater Groups such as the Esocidae which are the closest relatives of salmonids, have a karyotype comprising 25 pairs of acrocentric chromosomes and 48–52 chromosome arms. After the common ancestor of salmonids underwent a whole genome duplication, its karyotype would have 100 chromosome arms, and this is reflected in the modal range of 96–104 seen in extant salmonids (e.g., rainbow trout). The Atlantic salmon is an exception among the salmonids as it has 72–74 chromosome arms and its karyotype includes 12 pairs of large acrocentric chromosomes, which appear to be the result of tandem fusions. The purpose of this study was to integrate the Atlantic salmon's Linkage map and karyotype and to compare the chromosome map with that of rainbow trout. The Atlantic salmon genetic Linkage Groups were assigned to specific chromosomes in the European subspecies using fluorescence in situ hybridization with BAC probes containing genetic markers mapped to each Linkage group. The genetic Linkage Groups were larger for metacentric chromosomes compared to acrocentric chromosomes of similar size. Comparison of the Atlantic salmon chromosome map with that of rainbow trout provides strong evidence for conservation of large syntenic blocks in these species, corresponding to entire chromosome arms in the rainbow trout. It had been suggested that some of the large acrocentric chromosomes in Atlantic salmon are the result of tandem fusions, and that the small blocks of repetitive DNA in the middle of the arms represent the sites of chromosome fusions. The finding that the chromosomal regions on either side of the blocks of repetitive DNA within the larger acrocentric chromosomes correspond to different rainbow trout chromosome arms provides support for this hypothesis.
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Assignment of Atlantic salmon ( Salmo salar) Linkage Groups to specific chromosomes: Conservation of large syntenic blocks corresponding to whole chromosome arms in rainbow trout ( Oncorhynchus mykiss )
BMC Genetics, 2009Co-Authors: Ruth B. Phillips, Roy G Danzmann, Kimberly A. Keatley, Matthew R. Morasch, Abigail B. Ventura, Krzysztof P. Lubieniecki, Ben F. Koop, William S. DavidsonAbstract:Background: Most teleost species, especially freshwater Groups such as the Esocidae which are the closest relatives of salmonids, have a karyotype comprising 25 pairs of acrocentric chromosomes and 48– 52 chromosome arms. After the common ancestor of salmonids underwent a whole genome duplication, its karyotype would have 100 chromosome arms, and this is reflected in the modal range of 96–104 seen in extant salmonids (e.g., rainbow trout). The Atlantic salmon is an exception among the salmonids as it has 72–74 chromosome arms and its karyotype includes 12 pairs of large acrocentric chromosomes, which appear to be the result of tandem fusions. The purpose of this study was to integrate the Atlantic salmon's Linkage map and karyotype and to compare the chromosome map with that of rainbow trout. Results: The Atlantic salmon genetic Linkage Groups were assigned to specific chromosomes in the European subspecies using fluorescence in situ hybridization with BAC probes containing genetic markers mapped to each Linkage group. The genetic Linkage Groups were larger for metacentric chromosomes compared to acrocentric chromosomes of similar size. Comparison of the Atlantic salmon chromosome map with that of rainbow trout provides strong evidence for conservation of large syntenic blocks in these species, corresponding to entire chromosome arms in the rainbow trout. Conclusion: It had been suggested that some of the large acrocentric chromosomes in Atlantic salmon are the result of tandem fusions, and that the small blocks of repetitive DNA in the middle of the arms represent the sites of chromosome fusions. The finding that the chromosomal regions on either side of the blocks of repetitive DNA within the larger acrocentric chromosomes correspond to different rainbow trout chromosome arms provides support for this hypothesis.
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assignment of rainbow trout Linkage Groups to specific chromosomes
Genetics, 2006Co-Authors: Krista M. Nichols, Roy G Danzmann, Ruth B. Phillips, Kimberly A. Keatley, Matthew R. Morasch, Caird E Rexroad, Jenefer Dekoning, Scott A Gahr, Robert E DrewAbstract:The rainbow trout genetic Linkage Groups have been assigned to specific chromosomes in the OSU (2N = 60) strain using fluorescence in situ hybridization (FISH) with BAC probes containing genes mapped to each Linkage group. There was a rough correlation between chromosome size and size of the genetic Linkage map in centimorgans for the genetic maps based on recombination from the female parent. Chromosome size and structure have a major impact on the female:male recombination ratio, which is much higher (up to 10:1 near the centromeres) on the larger metacentric chromosomes compared to smaller acrocentric chromosomes. Eighty percent of the BAC clones containing duplicate genes mapped to a single chromosomal location, suggesting that diploidization resulted in substantial divergence of intergenic regions. The BAC clones that hybridized to both duplicate loci were usually located in the distal portion of the chromosome. Duplicate genes were almost always found at a similar location on the chromosome arm of two different chromosome pairs, suggesting that most of the chromosome rearrangements following tetraploidization were centric fusions and did not involve homeologous chromosomes. The set of BACs compiled for this research will be especially useful in construction of genome maps and identification of QTL for important traits in other salmonid fishes.
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assignment of zebrafish genetic Linkage Groups to chromosomes
Cytogenetic and Genome Research, 2006Co-Authors: Ruth B. Phillips, Angel Amores, M R Morasch, Catherine Wilson, John H PostlethwaitAbstract:In this report the zebrafish genetic Linkage Groups are assigned to specific chromosomes using fluorescence in situ hybridization (FISH) with BAC probes containing genes mapped to each Linkage group (LG). Chromosomes were identified using a combination of relative size and arm ratios. The largest genetic maps generally corresponded to the largest chromosomes, but genetic recombination tended to be elevated in the smaller chromosomes and near telomeres. Large insert clones containing genes near telomeres often hybridized to telomeres of multiple chromosome pairs, suggesting the presence of shared subtelomeric repetitive DNAs near telomeres. Evidence from comparative gene mapping in medaka, zebrafish, pufferfish, and humans suggests that the Linkage Groups of these species have the content of duplicate proto-chromosomes. However, these duplicate Linkage Groups are not associated with chromosomes of similar size or morphology. This suggests that considerable chromosome restructuring occurred subsequent to the genome duplication in teleosts.
Roy G Danzmann - One of the best experts on this subject based on the ideXlab platform.
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assignment of atlantic salmon salmo salar Linkage Groups to specific chromosomes conservation of large syntenic blocks corresponding to whole chromosome arms in rainbow trout oncorhynchus mykiss
BMC Genetics, 2009Co-Authors: Roy G Danzmann, Ruth B. Phillips, Kimberly A. Keatley, Matthew R. Morasch, Abigail B. Ventura, Krzysztof P. Lubieniecki, Ben F. Koop, William S. DavidsonAbstract:Most teleost species, especially freshwater Groups such as the Esocidae which are the closest relatives of salmonids, have a karyotype comprising 25 pairs of acrocentric chromosomes and 48–52 chromosome arms. After the common ancestor of salmonids underwent a whole genome duplication, its karyotype would have 100 chromosome arms, and this is reflected in the modal range of 96–104 seen in extant salmonids (e.g., rainbow trout). The Atlantic salmon is an exception among the salmonids as it has 72–74 chromosome arms and its karyotype includes 12 pairs of large acrocentric chromosomes, which appear to be the result of tandem fusions. The purpose of this study was to integrate the Atlantic salmon's Linkage map and karyotype and to compare the chromosome map with that of rainbow trout. The Atlantic salmon genetic Linkage Groups were assigned to specific chromosomes in the European subspecies using fluorescence in situ hybridization with BAC probes containing genetic markers mapped to each Linkage group. The genetic Linkage Groups were larger for metacentric chromosomes compared to acrocentric chromosomes of similar size. Comparison of the Atlantic salmon chromosome map with that of rainbow trout provides strong evidence for conservation of large syntenic blocks in these species, corresponding to entire chromosome arms in the rainbow trout. It had been suggested that some of the large acrocentric chromosomes in Atlantic salmon are the result of tandem fusions, and that the small blocks of repetitive DNA in the middle of the arms represent the sites of chromosome fusions. The finding that the chromosomal regions on either side of the blocks of repetitive DNA within the larger acrocentric chromosomes correspond to different rainbow trout chromosome arms provides support for this hypothesis.
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Assignment of Atlantic salmon ( Salmo salar) Linkage Groups to specific chromosomes: Conservation of large syntenic blocks corresponding to whole chromosome arms in rainbow trout ( Oncorhynchus mykiss )
BMC Genetics, 2009Co-Authors: Ruth B. Phillips, Roy G Danzmann, Kimberly A. Keatley, Matthew R. Morasch, Abigail B. Ventura, Krzysztof P. Lubieniecki, Ben F. Koop, William S. DavidsonAbstract:Background: Most teleost species, especially freshwater Groups such as the Esocidae which are the closest relatives of salmonids, have a karyotype comprising 25 pairs of acrocentric chromosomes and 48– 52 chromosome arms. After the common ancestor of salmonids underwent a whole genome duplication, its karyotype would have 100 chromosome arms, and this is reflected in the modal range of 96–104 seen in extant salmonids (e.g., rainbow trout). The Atlantic salmon is an exception among the salmonids as it has 72–74 chromosome arms and its karyotype includes 12 pairs of large acrocentric chromosomes, which appear to be the result of tandem fusions. The purpose of this study was to integrate the Atlantic salmon's Linkage map and karyotype and to compare the chromosome map with that of rainbow trout. Results: The Atlantic salmon genetic Linkage Groups were assigned to specific chromosomes in the European subspecies using fluorescence in situ hybridization with BAC probes containing genetic markers mapped to each Linkage group. The genetic Linkage Groups were larger for metacentric chromosomes compared to acrocentric chromosomes of similar size. Comparison of the Atlantic salmon chromosome map with that of rainbow trout provides strong evidence for conservation of large syntenic blocks in these species, corresponding to entire chromosome arms in the rainbow trout. Conclusion: It had been suggested that some of the large acrocentric chromosomes in Atlantic salmon are the result of tandem fusions, and that the small blocks of repetitive DNA in the middle of the arms represent the sites of chromosome fusions. The finding that the chromosomal regions on either side of the blocks of repetitive DNA within the larger acrocentric chromosomes correspond to different rainbow trout chromosome arms provides support for this hypothesis.
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assignment of rainbow trout Linkage Groups to specific chromosomes
Genetics, 2006Co-Authors: Krista M. Nichols, Roy G Danzmann, Ruth B. Phillips, Kimberly A. Keatley, Matthew R. Morasch, Caird E Rexroad, Jenefer Dekoning, Scott A Gahr, Robert E DrewAbstract:The rainbow trout genetic Linkage Groups have been assigned to specific chromosomes in the OSU (2N = 60) strain using fluorescence in situ hybridization (FISH) with BAC probes containing genes mapped to each Linkage group. There was a rough correlation between chromosome size and size of the genetic Linkage map in centimorgans for the genetic maps based on recombination from the female parent. Chromosome size and structure have a major impact on the female:male recombination ratio, which is much higher (up to 10:1 near the centromeres) on the larger metacentric chromosomes compared to smaller acrocentric chromosomes. Eighty percent of the BAC clones containing duplicate genes mapped to a single chromosomal location, suggesting that diploidization resulted in substantial divergence of intergenic regions. The BAC clones that hybridized to both duplicate loci were usually located in the distal portion of the chromosome. Duplicate genes were almost always found at a similar location on the chromosome arm of two different chromosome pairs, suggesting that most of the chromosome rearrangements following tetraploidization were centric fusions and did not involve homeologous chromosomes. The set of BACs compiled for this research will be especially useful in construction of genome maps and identification of QTL for important traits in other salmonid fishes.
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qtl for body weight and condition factor in atlantic salmon salmo salar comparative analysis with rainbow trout oncorhynchus mykiss and arctic charr salvelinus alpinus
Heredity, 2005Co-Authors: D P Reid, Roy G Danzmann, A Szanto, B D Glebe, Moira M FergusonAbstract:Genotypes at 91 microsatellite loci in three full-sib families were used to search for QTL affecting body weight (BW) and condition factor in North American Atlantic salmon (Salmo salar). More than one informative marker was identified on 16-18 Linkage Groups in each family, allowing at least one chromosomal interval to be analyzed per Linkage group. Two significant QTL for BW on Linkage Groups AS-8 and AS-11, and four significant QTL for condition factor on Linkage Groups AS-2, AS-5, AS-11, and AS-14 were identified. QTL for both BW and condition factor were located on Linkage Groups AS-1, 6, 8, 11, and 14 when considering both significant and suggestive QTL effects. The largest QTL effects for BW (AS-8) and for condition factor (AS-14) accounted for 20.1 and 24.9% of the trait variation, respectively. Three of the QTL for BW occur on Linkage Groups where similar effects have been detected on the homologous regions in either rainbow trout (Oncorhynchus mykiss) or Arctic charr (Salvelinus alpinus).
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a consolidated Linkage map for rainbow trout oncorhynchus mykiss
Animal Genetics, 2003Co-Authors: Krista M. Nichols, Roy G Danzmann, Ruth B. Phillips, William P Young, Barrie D Robison, Caird E Rexroad, Marc Noakes, Paul Bentzen, Ingrid B Spies, Kathy L KnudsenAbstract:Androgenetic doubled haploid progeny produced from a cross between the Oregon State University and Arlee clonal rainbow trout (Oncorhynchus mykiss) lines, used for a previous published rainbow trout map, were used to update the map with the addition of more amplified fragment length polymorphic (AFLP) markers, microsatellites, type I and allozyme markers. We have added more than 900 markers, bringing the total number to 1359 genetic markers and the sex phenotype including 799 EcoRI AFLPs, 174 PstI AFLPs, 226 microsatellites, 72 VNTR, 38 SINE markers, 29 known genes, 12 minisatellites, five RAPDs, and four allozymes. Thirty major Linkage Groups were identified. Synteny of Linkage Groups in our map with the outcrossed microsatellite map has been established for all except one Linkage group in this doubled haploid cross. Putative homeologous relationships among Linkage Groups, resulting from the autotetraploid nature of the salmonid genome, have been revealed based on the placement of duplicated microsatellites and type I loci.
William S. Davidson - One of the best experts on this subject based on the ideXlab platform.
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assignment of atlantic salmon salmo salar Linkage Groups to specific chromosomes conservation of large syntenic blocks corresponding to whole chromosome arms in rainbow trout oncorhynchus mykiss
BMC Genetics, 2009Co-Authors: Roy G Danzmann, Ruth B. Phillips, Kimberly A. Keatley, Matthew R. Morasch, Abigail B. Ventura, Krzysztof P. Lubieniecki, Ben F. Koop, William S. DavidsonAbstract:Most teleost species, especially freshwater Groups such as the Esocidae which are the closest relatives of salmonids, have a karyotype comprising 25 pairs of acrocentric chromosomes and 48–52 chromosome arms. After the common ancestor of salmonids underwent a whole genome duplication, its karyotype would have 100 chromosome arms, and this is reflected in the modal range of 96–104 seen in extant salmonids (e.g., rainbow trout). The Atlantic salmon is an exception among the salmonids as it has 72–74 chromosome arms and its karyotype includes 12 pairs of large acrocentric chromosomes, which appear to be the result of tandem fusions. The purpose of this study was to integrate the Atlantic salmon's Linkage map and karyotype and to compare the chromosome map with that of rainbow trout. The Atlantic salmon genetic Linkage Groups were assigned to specific chromosomes in the European subspecies using fluorescence in situ hybridization with BAC probes containing genetic markers mapped to each Linkage group. The genetic Linkage Groups were larger for metacentric chromosomes compared to acrocentric chromosomes of similar size. Comparison of the Atlantic salmon chromosome map with that of rainbow trout provides strong evidence for conservation of large syntenic blocks in these species, corresponding to entire chromosome arms in the rainbow trout. It had been suggested that some of the large acrocentric chromosomes in Atlantic salmon are the result of tandem fusions, and that the small blocks of repetitive DNA in the middle of the arms represent the sites of chromosome fusions. The finding that the chromosomal regions on either side of the blocks of repetitive DNA within the larger acrocentric chromosomes correspond to different rainbow trout chromosome arms provides support for this hypothesis.
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Assignment of Atlantic salmon ( Salmo salar) Linkage Groups to specific chromosomes: Conservation of large syntenic blocks corresponding to whole chromosome arms in rainbow trout ( Oncorhynchus mykiss )
BMC Genetics, 2009Co-Authors: Ruth B. Phillips, Roy G Danzmann, Kimberly A. Keatley, Matthew R. Morasch, Abigail B. Ventura, Krzysztof P. Lubieniecki, Ben F. Koop, William S. DavidsonAbstract:Background: Most teleost species, especially freshwater Groups such as the Esocidae which are the closest relatives of salmonids, have a karyotype comprising 25 pairs of acrocentric chromosomes and 48– 52 chromosome arms. After the common ancestor of salmonids underwent a whole genome duplication, its karyotype would have 100 chromosome arms, and this is reflected in the modal range of 96–104 seen in extant salmonids (e.g., rainbow trout). The Atlantic salmon is an exception among the salmonids as it has 72–74 chromosome arms and its karyotype includes 12 pairs of large acrocentric chromosomes, which appear to be the result of tandem fusions. The purpose of this study was to integrate the Atlantic salmon's Linkage map and karyotype and to compare the chromosome map with that of rainbow trout. Results: The Atlantic salmon genetic Linkage Groups were assigned to specific chromosomes in the European subspecies using fluorescence in situ hybridization with BAC probes containing genetic markers mapped to each Linkage group. The genetic Linkage Groups were larger for metacentric chromosomes compared to acrocentric chromosomes of similar size. Comparison of the Atlantic salmon chromosome map with that of rainbow trout provides strong evidence for conservation of large syntenic blocks in these species, corresponding to entire chromosome arms in the rainbow trout. Conclusion: It had been suggested that some of the large acrocentric chromosomes in Atlantic salmon are the result of tandem fusions, and that the small blocks of repetitive DNA in the middle of the arms represent the sites of chromosome fusions. The finding that the chromosomal regions on either side of the blocks of repetitive DNA within the larger acrocentric chromosomes correspond to different rainbow trout chromosome arms provides support for this hypothesis.
Ronald D Plattner - One of the best experts on this subject based on the ideXlab platform.
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a genetic map of gibberella zeae fusarium graminearum
Genetics, 2002Co-Authors: James E Jurgenson, Kurt A Zeller, John F Leslie, Robert L. Bowden, Nancy J Alexander, Ronald D PlattnerAbstract:We constructed a genetic Linkage map of Gibberella zeae ( Fusarium graminearum ) by crossing complementary nitrate-nonutilizing ( nit ) mutants of G. zeae strains R-5470 (from Japan) and Z-3639 (from Kansas). We selected 99 nitrate-utilizing (recombinant) progeny and analyzed them for amplified fragment length polymorphisms (AFLPs). We used 34 pairs of two-base selective AFLP primers and identified 1048 polymorphic markers that mapped to 468 unique loci on nine Linkage Groups. The total map length is ~1300 cM with an average interval of 2.8 map units between loci. Three of the nine Linkage Groups contain regions in which there are high levels of segregation distortion. Selection for the nitrate-utilizing recombinant progeny can explain two of the three skewed regions. Two Linkage Groups have recombination patterns that are consistent with the presence of intercalary inversions. Loci governing trichothecene toxin amount and type (deoxynivalenol or nivalenol) map on Linkage Groups IV and I, respectively. The locus governing the type of trichothecene produced (nivalenol or deoxynivalenol) cosegregated with the TRI5 gene (which encodes trichodiene synthase) and probably maps in the trichothecene gene cluster. This Linkage map will be useful in population genetic studies, in map-based cloning, for QTL (quantitative trait loci) analysis, for ordering genomic libraries, and for genomic comparisons of related species.
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A Genetic Map of Gibberella zeae (Fusarium graminearum)
Genetics, 2002Co-Authors: James E Jurgenson, Kurt A Zeller, John F Leslie, Robert L. Bowden, Nancy J Alexander, Ronald D PlattnerAbstract:We constructed a genetic Linkage map of Gibberella zeae (Fusarium graminearum) by crossing complementary nitrate-nonutilizing (nit) mutants of G. zeae strains R-5470 (from Japan) and Z-3639 (from Kansas). We selected 99 nitrate-utilizing (recombinant) progeny and analyzed them for amplified fragment length polymorphisms (AFLPs). We used 34 pairs of two-base selective AFLP primers and identified 1048 polymorphic markers that mapped to 468 unique loci on nine Linkage Groups. The total map length is approximately 1300 cM with an average interval of 2.8 map units between loci. Three of the nine Linkage Groups contain regions in which there are high levels of segregation distortion. Selection for the nitrate-utilizing recombinant progeny can explain two of the three skewed regions. Two Linkage Groups have recombination patterns that are consistent with the presence of intercalary inversions. Loci governing trichothecene toxin amount and type (deoxynivalenol or nivalenol) map on Linkage Groups IV and I, respectively. The locus governing the type of trichothecene produced (nivalenol or deoxynivalenol) cosegregated with the TRI5 gene (which encodes trichodiene synthase) and probably maps in the trichothecene gene cluster. This Linkage map will be useful in population genetic studies, in map-based cloning, for QTL (quantitative trait loci) analysis, for ordering genomic libraries, and for genomic comparisons of related species.
Matthew R. Morasch - One of the best experts on this subject based on the ideXlab platform.
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assignment of atlantic salmon salmo salar Linkage Groups to specific chromosomes conservation of large syntenic blocks corresponding to whole chromosome arms in rainbow trout oncorhynchus mykiss
BMC Genetics, 2009Co-Authors: Roy G Danzmann, Ruth B. Phillips, Kimberly A. Keatley, Matthew R. Morasch, Abigail B. Ventura, Krzysztof P. Lubieniecki, Ben F. Koop, William S. DavidsonAbstract:Most teleost species, especially freshwater Groups such as the Esocidae which are the closest relatives of salmonids, have a karyotype comprising 25 pairs of acrocentric chromosomes and 48–52 chromosome arms. After the common ancestor of salmonids underwent a whole genome duplication, its karyotype would have 100 chromosome arms, and this is reflected in the modal range of 96–104 seen in extant salmonids (e.g., rainbow trout). The Atlantic salmon is an exception among the salmonids as it has 72–74 chromosome arms and its karyotype includes 12 pairs of large acrocentric chromosomes, which appear to be the result of tandem fusions. The purpose of this study was to integrate the Atlantic salmon's Linkage map and karyotype and to compare the chromosome map with that of rainbow trout. The Atlantic salmon genetic Linkage Groups were assigned to specific chromosomes in the European subspecies using fluorescence in situ hybridization with BAC probes containing genetic markers mapped to each Linkage group. The genetic Linkage Groups were larger for metacentric chromosomes compared to acrocentric chromosomes of similar size. Comparison of the Atlantic salmon chromosome map with that of rainbow trout provides strong evidence for conservation of large syntenic blocks in these species, corresponding to entire chromosome arms in the rainbow trout. It had been suggested that some of the large acrocentric chromosomes in Atlantic salmon are the result of tandem fusions, and that the small blocks of repetitive DNA in the middle of the arms represent the sites of chromosome fusions. The finding that the chromosomal regions on either side of the blocks of repetitive DNA within the larger acrocentric chromosomes correspond to different rainbow trout chromosome arms provides support for this hypothesis.
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Assignment of Atlantic salmon ( Salmo salar) Linkage Groups to specific chromosomes: Conservation of large syntenic blocks corresponding to whole chromosome arms in rainbow trout ( Oncorhynchus mykiss )
BMC Genetics, 2009Co-Authors: Ruth B. Phillips, Roy G Danzmann, Kimberly A. Keatley, Matthew R. Morasch, Abigail B. Ventura, Krzysztof P. Lubieniecki, Ben F. Koop, William S. DavidsonAbstract:Background: Most teleost species, especially freshwater Groups such as the Esocidae which are the closest relatives of salmonids, have a karyotype comprising 25 pairs of acrocentric chromosomes and 48– 52 chromosome arms. After the common ancestor of salmonids underwent a whole genome duplication, its karyotype would have 100 chromosome arms, and this is reflected in the modal range of 96–104 seen in extant salmonids (e.g., rainbow trout). The Atlantic salmon is an exception among the salmonids as it has 72–74 chromosome arms and its karyotype includes 12 pairs of large acrocentric chromosomes, which appear to be the result of tandem fusions. The purpose of this study was to integrate the Atlantic salmon's Linkage map and karyotype and to compare the chromosome map with that of rainbow trout. Results: The Atlantic salmon genetic Linkage Groups were assigned to specific chromosomes in the European subspecies using fluorescence in situ hybridization with BAC probes containing genetic markers mapped to each Linkage group. The genetic Linkage Groups were larger for metacentric chromosomes compared to acrocentric chromosomes of similar size. Comparison of the Atlantic salmon chromosome map with that of rainbow trout provides strong evidence for conservation of large syntenic blocks in these species, corresponding to entire chromosome arms in the rainbow trout. Conclusion: It had been suggested that some of the large acrocentric chromosomes in Atlantic salmon are the result of tandem fusions, and that the small blocks of repetitive DNA in the middle of the arms represent the sites of chromosome fusions. The finding that the chromosomal regions on either side of the blocks of repetitive DNA within the larger acrocentric chromosomes correspond to different rainbow trout chromosome arms provides support for this hypothesis.
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assignment of rainbow trout Linkage Groups to specific chromosomes
Genetics, 2006Co-Authors: Krista M. Nichols, Roy G Danzmann, Ruth B. Phillips, Kimberly A. Keatley, Matthew R. Morasch, Caird E Rexroad, Jenefer Dekoning, Scott A Gahr, Robert E DrewAbstract:The rainbow trout genetic Linkage Groups have been assigned to specific chromosomes in the OSU (2N = 60) strain using fluorescence in situ hybridization (FISH) with BAC probes containing genes mapped to each Linkage group. There was a rough correlation between chromosome size and size of the genetic Linkage map in centimorgans for the genetic maps based on recombination from the female parent. Chromosome size and structure have a major impact on the female:male recombination ratio, which is much higher (up to 10:1 near the centromeres) on the larger metacentric chromosomes compared to smaller acrocentric chromosomes. Eighty percent of the BAC clones containing duplicate genes mapped to a single chromosomal location, suggesting that diploidization resulted in substantial divergence of intergenic regions. The BAC clones that hybridized to both duplicate loci were usually located in the distal portion of the chromosome. Duplicate genes were almost always found at a similar location on the chromosome arm of two different chromosome pairs, suggesting that most of the chromosome rearrangements following tetraploidization were centric fusions and did not involve homeologous chromosomes. The set of BACs compiled for this research will be especially useful in construction of genome maps and identification of QTL for important traits in other salmonid fishes.