Protein polymorphisms of Goats in Tunisian Oases

The main objective of this study was to assess the genetic variation between the two goat populations in the region of Tozeur, Arbi and Serti, by means of blood protein polymorphism. A total of 97 animals from two indigenous goat types were investigated. The determination of red cell lysates and plasma proteins were carried out by starch gel electrophoresis. Two alleles were detected at all loci investigated; haemoglobin, transferrin, carbonic anhydrase, albumin and X-protein for each populations. Esterase was typed as described by Tucker et al. (1967)19, where two phenotypic variants occurred, namely EsA-positive and EsA-negative. In most cases, the observed genotype frequencies were not significantly different from that expected under Hardy-Weinberg equilibrium except for carbonic anhydrase. The mean number of alleles per locus was between 1.61 and 1.67 for the Arbi and the Serti populations, respectively. The expected mean heterozygosities were between 0.29 and 0.38 while the observed mean heterozygosities were from 0.34 to 0.38. Most of the diversity obtained was located within populations. Cluster analysis based on Nei (1972)9 standard genetic distance and Nei (1978)11 standard genetic distance and Unweighted Pair Group Method with Arithmetic Mean dendrogram revealed low level of genetic distance between populations and relatively higher genetic distance within populations.