MURINE ALBINO-DELETION COMPLEX - HIGH-RESOLUTION MICROSATELLITE MAP AND GENETICALLY ANCHORED YAC FRAMEWORK MAP

The murine albino-deletion complex developed as part of the Oak Ridge specific-locus test covers 6-11 cM of chromosome 7. This complex has p roven to be a valuable resource for localizing traits to a small targe t region suitable for positional cloning. In this study, we mapped the endpoints of deletions in this complex using all of the available Mit simple-sequence length polymorphism (SSLP) markers. Concurrently, thi s mapping has determined the map order of nearly all of the SSLP marke rs, most of which were previously unresolved. The SSLP-based deletion map was confirmed and genetic distances were determined using the Euro pean Collaborative Interspecific Backcross panel of nearly a thousand mice. The average SSLP marker resolution is 0.3-0.4 cM, comparable to the cloning capacity of yeast artificial chromosomes (YACs). The SSLP markers were then used to construct a genetically anchored YAC framewo rk map that further confirms the deletion map. We find that the larges t deleted region distal to Tyr is about two to three times larger than the largest proximal deleted region, and the original C3H/101 regions flanking the deletions (moved to an St2A c(ch)/c(ch) background) are smaller than anticipated, which we suggest may result from increased r ecombination rates immediately flanking the deleted regions.