Research On Blood Protein Polymorphisms And Prolificacy Of Small-tailed Han Sheep

Nine blood protein loci from six sheep populations were analyzed using vertical discontinuous polyacrylamide gel electrophoresis(PAGE) in six sheep types. The 9 protein loci were Haemoglobin(Hb), Transferring(Tf), Albumin(Alb), Prealbumin(Pr), Erythrocyte protein(Ep), Esterase(Es), Amylase(AMY), Lactic dehydrogenase(LDH) and Serum alkaline plospgatase(AKP). Blood samples were from six sheep populations including Small tailed Han sheep , Tan sheep, Gansu Alpine Merino, Qinghai Merino, Tibetan sheep in Gasu, Tibetan sheep in Qinghai. In order to know completely blood protein (enzyme) polymorphism of Small tailed Han shep, relationship between blood protein genetic characters and prolificacy of Small tailed Han sheep was analysed. Secondly using those genetic characters of blood protein (enzyme)polymorphisms, average heterozygosity,Allele frequencies,effective number of allele, gene diversity,genetic distance was calculated as a measure of genetic similarity between the populations and the degree of genetic variability,and the correlation between Small tailed Han sheep and other breeds was discussed by the constructed phylogenetic tree.AIb and Pr were monomorphic while Hb, Tf and Es were polymorphisms in all sheep populations. AMY was monomorphic in Small tailed Han sheep, Tan sheep, Gansu Alpine Merino and was polymorphisms in Qinghai Merino, Tibetan sheep in Gasu, Tibetan sheep in Qinghai. Meanwhile Ep was polymorphism in Small tailed Han sheep, Qinghai Merino, Tibetan sheep in Qinghai, Tibetan sheep in Gasu and wasn't polymorphisms in Gansu Alpine Merino and Tan sheep.There were five kinds isozymes of LDH (LDH1, LDH2, LDH3, LDH4, LDH5 ) in other sheep breeds or types ,but there were no LDH4 Tibetan sheep in Qinghai. AKP's testing effect was not good enough to be analysed in all protein loci.The relationship between blood protein loci polymorphisms and prolificacy of Small tailed Han sheep as following:There was a relationship between HbB gene of Hb, TfC gene of Tf, Es－ gene of Es and prolificacy of Small tailed Han sheep;Whether Ep could be used as the genetic marker of the prolificacy of Small tailed Han sheep should be discussed further. There were no linkage between all the marker loci and the major effect genes researched such as prolific gene FecB, but there were relationship between them. Thus, further research was needed to discuss whicn kind of blood protein loci can be used as genetic marker of sheep prolificacy to discover the relationship between sheep prolific traits and major effect genes. The genetic variation was more serious Tibetan sheep in Gasu and Tibetan sheep in Qinghai(2.0377,2.1972) obtained from Nei's expected genetic heterozygosity, the numbers of effect allele.The genetic variation ratio of Gansu Alpine Merino was higher than Qinghai Merino(1.8066,1.8561),and Small tailed Han sheep's variation ratio was between Gansu Alpine Merino and Qinghai Merino(1.8184). Tan sheep's variation degree was the lowest(1.7188).The cluster analysis showed that the genetic distance (0.0036) between Gansu Alpine Merino and Qinghai Merino was the nearest.Due to history reasons, Small tailed Han sheep have merino sheep gene, it have nearer genetic distance with two merino breeds(0.0062,0.0053). Tan sheep and Gansu Alpine Merino also had nearer genetic distance(0.0071), however the genetic diatance between Tibetan sheep in Gasu and Tibetan sheep in Qinghai was the nearer than other sheep breeds, because they are two indigenous sheep types of Tibetan sheep.