Identification And Primary Studies Of Genes Correlated With Wool Characters

Chinese merino sheep is one of choice genetic resources because of its wool production and characters, but compared with Australian Merino sheep and other better species, there is a long way to go. How to contract, even surpass this distinction has been an important and urgent task for Chinese sheep breeding workers. However this target can not be achieved by normal breeding methods, more and more sheep breeding workers resort to gene operation, they try to find genes correlated with wool characters, then promote wool production or improve wool characters by molecular manipulation.Firstly, the study applied mRNA differential display technique to isolate differential expressed genes in different parts of sheep skin (shoulder, abdomen and mid-leg), and obtained 4 differential display genes, then the 4 gene fragments were cloned, sequenced and proceeded biological information analysis by blastn ,but no identical sequences were founded in Genbank of NCBI. Highest identical sequences were selected to anticipate function of the 4 differential genes, but the results had much differences with original anticipation .To confirm whether the differential genes associated with wool characters, their expression was detected in wool follicles by tissue in situ hybridization. The results showed 4 genes expressed in wool follicles, it implied 4 gene fragments transcript to mRNA in wool follicles, but their whole sequences and function should be studied further.Besides, in this study, GHR gene expression was detected in wool follicles by tissue in situ hybridization. GHR is receptor of GH, GH's function is effected by two ways: One is that GH reacts to GHR in liver, then produces insulin-like growth factors (IGFs), the latter reacts to IGF receptors(IGFR) and modulates animal growth and tissue development; Another is that GH directly reacts to its receptors in the target tissues, then modulates cell metabolism by side-secretion or self-secretion. The results of the study showed that GHR gene expresses in wool follicles, so , there is direct effect of GH in wool growth.