The Functions And Regulatory Mechanism Of P57 In Mouse Mammary Development And Milk Secretion

Imprinted gene is a kind of parental origin-specific expression gene,researches shows that the majority of imprinted genes play an important role in embryonic development,the formation of the placenta and individual life.P57 is a cyclin-kinase inhibitor,it is a typical tumor suppressor genes,which is also a paternal imprint,maternal expression gene,its deletion will bring embryonic lethality.P57 protein immunofluorescence staining showed it's widely expressed in mammary gland,RT-PCR results showed that its expression decline during the four stage Mammary gland development.In order to study the role of P57 in the Mammary gland development,I designed two kinds of shRNA to knockout P57,and find P57 influence the mammary epithelial cells' proliferation by affecting the stemness of mammary stem cell.Genes in stem cell signaling pathway expression levels were significantly reduced while the cycle experiments showed that the number of cells in G1 phase was reduce,which instructions for dividing cells raised.Deletion of adjacent LncRNA Kcnq1ot1 promote P57's expression,but the deletion of PRC2's member Suz12 cannot affect P57 while the Kcnq1ot1's expression reduce.After P57 was knocked out,the expression levels of another 15 imprinted genes were changed,suggesting the presence of imprinting network in mammary.