GENETIC LINKAGE MAPS OF MICROSATELLITES IN THE TILAPIA GENOME

Biosoft AS, Oslo Research Park, Gaustadalleen 21 N-0371 Oslo, Norway

In an attempt to develop better breedig programs for commercial fish farming (using marker assisted selection for commercially important traits), we are constructing a detailed genetic linkage map for a tilapia family with about 500 microsatellite markers including some of the previously published ones (Kocher et al., 1998). We isolated the microsatellite markers from a single individual of O. niloticus and a hybrid between O. niloticus and O. aureus, and genotyped 70 full-sibs of a F₂ generation of the cross between Oreochromis niloticus and Oreochromis aureus. Based on the early estimation of the tilapia genome size, the complete linkage map contains markers in every 2-3 cM distance, which will provide an excellent basis for QTL hunting and on-going physical mapping procedures.