Plant & Animal Genomes XI Conference Plant & Animal Genomes XI ConferenceJanuary 11-15, 2003
Town & Country Convention Center
San Diego, CA
Workshop: Aquaculture
Segregation of AFLP markers was analyzed for sex-linked polymorphisms in rainbow trout. Fish were generated from an outbred mother by a (OSU x SW) F1 hybrid father. A total of 486 primer combinations were screened in DNA pool samples (6 pools/sex; 4-5 fish/pool). The polymorphisms found were individually analyzed in the progeny (n = 245 fish).Eleven male-associated and five female-associated AFLP markers were identified. A genetic map for the rainbow trout sex determining region was developed showing locations of sex AFLP polymorphic loci. All AFLP fragments were converted into SCARs and used for sex identification. The SCAR Omy-163 showed that it was inherited in a sex linked manner in our progeny as well as in other rainbow trout strains including: a) OSU x CW cross, b) OSU x ARL cross, and c) an outbred Kamloops population. Karyotype analysis of the three male rainbow trout clonal lines (SW, CW, ARL) demonstrated morphological differences of the Y chromosome. ARL and SW had a subtelocentric chromosome pair (YY), which showed a high similarity to the X chromosomes of OSU (XX). However, the Y chromosomes in SW had a short arm smaller that the short arm on the subtelocentric chromosomes in ARL. The Y chromosomes were telocentric in CW (YY). Thus, molecular analysis in combination with cytogenetic studies suggest that the SCAR Omy-163 is not strain-specific but Y-chromosome specific. The sex locus in these male research strains is apparently located on the same linkage group and there appears to be a polymorphism in Y chromosome morphology any the strains.