The Influence Of Prolactin On The Proliferation And Differentiation In Vitro Of Dairy Cow's Mamary Stem Cell

Holstein has the characteristics of strong physique,strong adaptability and large milk production.It is raised in most parts of China.In order to increase its milk production,a small molecule of polypeptide hormone,prolactin(PRL),was applied to dairy cows during the promoting lactation process.This experiment mainly studied the effect of PRL on the proliferation and differentiation of mammary stem cells cultured in vitro.Firstly,the mammary stem cells isolated in laboratory were purified by mechanical scraping,and then identified by the methods of differentiation induction and marker gene detection.Secondly,different concentrations of PRL were chosen to stimulate mammary stem cells.And then the MTT assay and Real-time PCR were used to study the optimal concentration of PRL in promoting the proliferation and differentiation of mammary stem cells in vitro.The results of the study are as follows:1.The induction of the purified mammary stem cells from the mechanical removal method proves that it has multiple potentials of differentiation into osteoblasts,lipids,and nerves,and can express a variety of dry genes.2.PRL was treated with 5 concentrations of 0,100,300,500 and 700 ng/mL,and was analyzed by MTT assay.500 ng/mL PRL was the most suitable for the prolife ration of breast stem cells in vitro.3.Use 0ng/mL,100 ng/mL,300 ng/mL,500 ng/mL,700 ng/mL five levels of PRL stimulate mammary gland stem cells,respectively in 0 d,1 d,3 d,5 d,7 d,9 d,11 d and 14 d cells extracted total RNA,RealtimePCR method measuring the mammary gland stem cell marker genes PROCR,Sca-1,epithelial marker genes CK8 three ge ne ex-pression.The results showed that the expression of CK8 was the largest in vit ro culture of 100 ng/mL PRL.When 700 ng/mL PRL,PROCR and Sca-1 are the m ost expre-ssed.