| 一. Microsatellite Analysis of Genetic Diversity of Sheep Breeds in XinjiangTo reveal the genetic diversity and systemic relationship of main sheep breeds in north Xingjiang, the genetic polymorphisms of 10 microsatellites in 8 sheep breeds and 1 first filial generation (F1) in north Xinjiang were studied by means of PCR, polyacrylamide gel electrophoresis and silver staining. Number of alleles, average effective number of alleles (E) and average rates of homozygote of each breeds were counted. According to allele frequencies of ten microsatellites, polymorphism information content (PIC), mean heterozygosity (h) and genetic distances were calculated for each breeds. By using the Neighbor-joining method of Molecular Evolutionary Genetics Analysis software, a dendrogram were obtained based on genetic distances. Another dendrogram were obtained by Maximum Likelihood method in PHYLIP (3.6) software. The bootstrap values were evaluated for each crunode of the dendrogram by means of bootstrap test. The systemic relationship was analyzed as well. The results showed that 8 of 10 microsatellite loci were high polymorphic, but BM1824 and MAF65 were low and medium polymorphic respectively, so the 8 microsatellite loci were effective markers for analysis of genetic relationship among sheep breeds. The average PIC (0.5631), h ( 0.5721) and E (2.9) of the whole population were all lower than those of other sheep breeds reported in the documents, which showed the gene polymorphisms and genetic diversity in these sheep breeds are relatively rare. The genetic distances of native Aletai, Kazak and Bashibai sheeps in Xingjiang from foreign sheep breeds and cultivated breeds bearing foreign bloodline are relatively large. Consequently, they clustered in two groups. The phylogenetic relationship between different sheep breeds was hi accordance with their resourse, breeding history, differentiation and localities.二. Expression of Target genes for Growth hormone Action in Skin of Sheep and Their Role of Wool Growth1. Developmental changes of the body weight of hair sheep and wool sheep, the growth of wool, and the expression of genes encoding GH, IGF-1 and IGF-1R in the skin of sheep.To investigate the neuroendocrine mechanisms of wool growth, two sheep breeds were selected for the experiments, one breed is first filial generation (Fl) of Romilly Hillys x Merino of China (Xinjiang Agricultural Reclamation line) wool sheep, and the other is Kazak hair sheep. Sheep were weighed and wool were sampled and evaluated at 30, 60, 90, 135, 180 and 255 days of age respectively, and skin were sampled at 30, 90, 135 and 255 days of age respectively, meanwhile, the relative mRNA abundance of growth hormone (GH), Insulin-like growth factor-1 (IGF-1), and IGF-1 receptor (IGF-1R) was measured in all selected skins, with relative quantitative reverse transcription-polymerase chain reaction (RT-PCR) using 18S rRNA as an internal standard.1.1 Developmental changes of body weight gain and the wool growth.The same developmental patterns were observed in average daily body weight gain (ADG) and wool growth between two sheep breeds, i.e. ADG of lambs decreased and average daily wool length gain (ADL) increased as the age increased. The ADG (PO.01) and ADL (PO.01) of hair sheep were all significantly higher than those of wool sheep during 30-90 days, but ADG not during 90-255 days between two breeds, while, ADL of hair sheep was evidently lower than that of wool sheep during 90-135 days (P<0.01), there was no significant difference during 135-255 days. ADG showed no sexual discrepancy for each breed, whereas, male hair sheep had higher ADL than female during 90-180 days (P<0.01), and ADL of male wool sheep was significantly higher than that of females 60-90 days.1.2 Developmental changes of the GHR, IGF-1 and IGF-1R mRNA abundance in skin.The pattern of developmental changes of the GHR, IGF-1 and IGF-1R mRNA abundance in skin from hair sheep and wool sheep was similar. i> The relative abundance of GHR mRNA in skin of hair sheep incre...
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