title: Assignment of rainbow trout linkage groups to specific chromosomes.
abstract: 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.
authors.affiliation: Department of Biological Sciences, Washington State University, Vancouver, Washington 98686-9600, USA. phllipsr@vancouver.wsu.edu
authors.forename: Ruth B
authors.initials: RB
authors.lastname: Phillips
authors.forename: Krista M
authors.initials: KM
authors.lastname: Nichols
authors.forename: Jenefer J
authors.initials: JJ
authors.lastname: DeKoning
authors.forename: Matthew R
authors.initials: MR
authors.lastname: Morasch
authors.forename: Kimberly A
authors.initials: KA
authors.lastname: Keatley
authors.forename: Caird
authors.initials: C
authors.lastname: Rexroad
authors.forename: Scott A
authors.initials: SA
authors.lastname: Gahr
authors.forename: Roy G
authors.initials: RG
authors.lastname: Danzmann
authors.forename: Robert E
authors.initials: RE
authors.lastname: Drew
authors.forename: Gary H
authors.initials: GH
authors.lastname: Thorgaard
mesh_terms: D000818:Animals; D002874:Chromosome Mapping; D002875:Chromosomes; D022202:Chromosomes, Artificial, Bacterial; D015342:DNA Probes; D021901:DNA, Intergenic; D004171:Diploidy; D005260:Female; D020131:Genes, Duplicate; D008040:Genetic Linkage; D005819:Genetic Markers; D017404:In Situ Hybridization, Fluorescence; D007621:Karyotyping; D018895:Microsatellite Repeats; D017686:Oncorhynchus mykiss / Q000235:genetics*; D011995:Recombination, Genetic
chemical_list: D015342:DNA Probes; D021901:DNA, Intergenic; D005819:Genetic Markers