MAPPING 28 ERYTHROCYTE ANTIGEN, PLASMA-PROTEIN AND ENZYME POLYMORPHISMS USING AN EFFICIENT GENOMIC SCAN OF THE PORCINE GENOME

One hundred and fifty-four microsatellite markers were selected for ge nomic scanning of the porcine genome and were grouped into amplificati on sets to reduce the cost and labour required. Thirty amplification s ets had two markers (duplex), 20 sets had three markers (tripler) and five sets had four markers (quadruplex) while 14 markers were analysed separately. The selection criteria for microsatellites were: ease of scoring, level of polymorphism, genetic location and ability to be gen otyped in a multiplexed polymerase chain reaction (PCR). The selected microsatellites were chosen to span the entire genome flanked by the p orcine linkage map with intervals between adjacent markers of 15-20 cM where possible. The utility of this set of markers was demonstrated b y linkage analyses with loci controlling blood plasma protein and red cell enzyme polymorphisms (n = 13), erythrocyte antigens (n = 15), the S blood group, coat colour and ryanodine receptor from 174 backcross Meishan-White Composite pigs. These loci displayed various forms of in heritance and most (24 loci) have been placed in linkage groups. Signi ficant two-point linkages (lod > 3.0) were detected for each polymorph ic marker. These results provide the first linkage assignments for pho sphoglucomutase (PGM2) and erythrocyte antigen F (EAF) to SSC8; and se rum amylase (AMY) and erythrocyte antigen I (EAI) to SSC18. All of the remaining polymer phic loci (n = 24) mapped to previously identified regions confirming earlier results. Most of the markers used in this s tudy should be useful in resource populations of various breed crosses as the number of alleles detected in a multibreed reference populatio n was one of the selection criteria.