부산대학교 도서관

The bovine erythrocyte membrane carries Rhesus (Rh)-like proteins. To obtain a bovine nucleotide probe, a cDNA library of foetal liver was constructed and screened with the human RhCE probe. Three clones (245 bp, 1012 bp and 1400 bp) were isolated and sequenced. They share a high degree of similarity (up to 73%) with Rh-like cDNAs of primates characterized so far and all of them were shown to contain a polymorphic microsatellite in their 3′ untranslated region. Their sequences support the occurrence of different splicing isoforms transcribed from the same RH-like gene. One of the clones (1400 bp), which has a 134-nucleotide deletion causing a frameshift, is structurally similar to the human Rh4 cDNA isoform. Synteny mapping and genetic linkage analysis located the bovine RH-like locus on chromosome BTA2, on which none of the 10 previously mapped blood group systems are found. In situ hybridization mapped the RH-like locus to BTA2q45. No linkage was detected between the microsatellite and the only unmapped blood group system (locus F). These results strongly suggest that the putative bovine Rh-like polypeptides do not correspond to any previously described bovine blood group. Comparative studies of human and bovine maps clearly show that the human RH locus, which is located on HSA1p34-p36, and its bovine counterpart belong to a linkage group highly conserved between both species.