Plant & Animal Genome VI Conference

P344

A DETAILED LINKAGE MAP OF RAINBOW TROUT PRODUCED USING DOUBLED HAPLOIDS

1. Department of Biological Sciences, Northern Arizona University, Flagstaff AZ 86011
2. Department of Zoology, Washington State University, Pullman WA 99164
3. Department of Genetics and Cell Biology, Washington State University, Pullman WA 99164

We report the first detailed genetic linkage map of rainbow trout (Oncorhynchus mykiss). The segregation analysis was performed using 76 doubled haploid (DH) rainbow trout produced by androgenesis from a hybrid between the "OSU" and "Arlee" androgenetically-derived homozygous lines. Four hundred and eighty-one markers segregated into 31 major linkage groups and 10 small groups (< 4 markers/group). The minimum genome size is estimated to be 2627.5 cM in length. The sex-determining locus segregated to a distal position on one of the linkage groups. We analyzed the chromosomal distribution of three classes of markers: amplified fragment length polymorphisms (AFLP), variable number of tandem repeats (VNTR) and markers obtained using probes homologous to the 5' or 3' end of salmonid-specific small interspersed nuclear elements (SINEs). Many AFLP markers were clustered in regions of reduced recombination that appear to correspond to centromeres. VNTR markers were more telomeric in distribution and SINEs were intermediate. Tetrasomic inheritance, apparently related to the tetraploid ancestry of salmonid fishes, was detected at one simple sequence repeat locus and suggested by the presence of one extremely large linkage group that appeared to consist of two smaller groups linked at their tips. The DH rainbow trout lines and linkage map present a foundation for further genomic studies.