Study on molecular mechanism for regulation of maternal behavior with prolactin-knockout mice

点击翻译按钮获取中文摘要

1. Phenotype analysis of prolactin-knockout (PRL-KO) miceProlactin-deficient mice were produced by the turgeted disruption of prolactin gene. No abnormal phenotype was obserbed in malePRL-KO mice. However, the mutation caused infertility in female mice because of the inability of implantation of the firtilized eggs. Mammary glands of PRL-KO mice developed a normal ductal tree, but the ducts failed to develop lobular decorations. These findings indicate that PRL is essential for the fertility and mammary gland development of female mice.2. Analysis of maternal behavior of PRL-KO micePRL-KO mice were tested for maternal behavior (pup retrieval and crouching) toward 2-4 days old foster pups. The maternal behavior of PRL-KO mice were equivalent to those of wild-type mice, indicating that PRL, is not essential for the spontaneous maternal behavior. The PRL effect on induction of maternal behavior might be compensated by other hormones such as estrogen. progesteron and oxytocin.3. Analysis of expression levels of PRL-receptor in the chicken brain during incubation behavior.PRL is known to induce incubation behavior of chicken by acting on its receptor in the hypothalamus. High level expression of the PRL receptor was observed in the hypothalamus but the level was not increased during the incubating period. Therefore, the PRL effect on the induction of incubation behavior is regulated by the ligand level, not by the receptor level.