Radiation hybrid maps of candidate trypanotolerance chromosomal regions incattle

A preliminary search for QTLs in a cattle F2 resource population segregatin g for trypanotolerance has revealed three large candidate chromosomal regio ns (Bta02, Bta05, Bta07). In order to narrow down the position of the trypa notolerant QTLs, we are building comparative chromosomal maps between cattl e, human and mice. Using a cattle radiation hybrid panel, first framework m aps are constructed with type II markers (microsatellites). Then, type I ma rkers (genes) are positioned within these maps. Their relative chromosomal positions, compared to their positions in human and mice, allow us to defin e conserved syntenic regions between the three species. The large number of genes being identified in human and mice may assist selection of candidate genes.