A medium density microsatellite map of BTA10: reassignment of INRA69

We have developed a genetic map of BTA10 based on 8952 informative meioses for 13 microsatellite markers and the erythrocyte antigen Z. With the exception of OarAE64, the support for the order of all loci in the map exceeded a LOD > 3.0. The length of the BTA10 genetic map was 87.0 centimorgans (cM). The 14-marker, sex-average map in Kosambi cM was: CSSM38-8.9-BM1237-5.2-HH8A-2.6- INRA69-10.6-TGLA378-0.8-BM6305-17.2- TGLA102-17.9-INRA96-0.3-CSRM60-9.2- DIK20-3.0-EAZ-6.7-CSSM46-3.7-SRCRSP3-1.0-OarA E64 with an average interval of 6.70 cM. The microsatellite INRA69 was recently assigned to the pseudoautosomal region of the bovine X chromosome by linkage analysis. However, we found that twopoint support for linkage between INRA69 and 15 X-linked bovine microsatellites was LOD < 0.50 in 529 reciprocal backcross and F2 fullsib progeny. We performed twopoint analyses of INRA69 against 275 markers distributed throughout the bovine genome and found significant associations with a LOD > 3.0 only between INRA69 and eight BTA10 microsatellite loci. Consequently, we excluded INRA69 from the genetic map of the X chromosome and reassign this microsatellite to BTA10.