FURTHER-STUDIES ON THE POPULATION-GENETICS OF THE BLESBOK DAMALISCUS-DORCAS-PHILLIPSI

For approximately 100 years blesbok - endemic to South Africa - have b een extinct in the wild and confined to fenced game reserves or farms. Biochemical-genetic variation was studied in blesbok from five isolat ed populations using electrophoretic allozyme analysis. Body weights a nd liver mineral concentrations were also determined. Material was col lected from three localities in the Orange Free State province: a larg e reserve (PRE, ca 10 000 ha, N = 500-600, n = 23); a smaller reserve (KOP, ca 3 000 ha, N = 150-200, n = 14) with animals derived from the same source; and a farm (MID, ca 4 000 ha, N = up to 700, n = 19). The other two localities were a farm in the northern Cape Province (BEN, ca 10 000 ha, N = 200, n = 18) and another in the southern Cape Provin ce (BRA, ca 150 ha, N = 50-80, n = 27), both with populations derived from small founder stocks. Three loci were polymorphic: Pgm-1, Acy-1, and Gpi-1 but Acy-1 was the only one polymorphic in all five populatio ns. Pgm-1 was polymorphic in two populations derived from the same sou rce and Gpi-1 in the other from the Orange Free State. Calculated over 45 presumptive structural loci the mean proportion of polymorphic loc i (P) was 3.5% (SD = 1.2%), and mean expected average heterozygosity ( H-e) was 0.9% (SD = 0.25%). The populations separated out by genetic d istance in two distinct groups, those from the Cape Province and those from the Orange Free State. There were considerable differences in me an body weight between some sites. No correlation could be detected wi th level of heterozygosity. Body weight appeared rather to be related to liver mineral levels. In particular the ratio between copper and mo lybdenium appears important with those animals high in copper and low in molybdenium having a higher body weight.