MAPPING OF BOVINE FC-GAMMA-R (FCGR) GENES BY SPERM TYPING ALLOWS EXTENDED USE OF HUMAN MAP INFORMATION

Polymorphic sites within the bovine Fc gamma RI (FCGR1), Fc gamma RII (FCGR2), and Fc gamma RIII (FCGR3) genes were used for proximal mappin g of these genes to bovine Chromosome (Chr) 3 (BTA3) with paternal hal f-sib families from Norwegian Cattle. A fine-structure genetic map of the region was obtained by the analysis of 288 sperm cells from three bulls that were heterozygous for the loci included in the study. No re combinants were observed between FCGR2 and FCGR3 (242 sperm cells). Co nsidering FCGR2 and FCGR3 as a single locus, a three-point linkage ana lysis for [FCGR2/FCGR3], FCGR1, and INRA003 was carried out. The best- supported order of the loci was found to be INRA003-FCGR1-[FCGR2/FCGR3 ]. Map distances in a two-point linkage analysis were 10.3 cM between [FCGR2/FCGR3] and FCGR1, and 25.5 cM between FCGR1 and INRA003, respec tively. This linkage mapping of the bovine FCGR gene family resembles the human situation where all FCGR genes are located at Chr 1 (HSA1), at position q21-q24. Moreover, the results locate the evolutionary bre akpoint between HSA1q and BTA3 within the human 1q24 region.