Molecular Regulation of Delayed Implantation in Mammals

Abstract: Delayed implantation occurs when the conceptus enters a state of suspended animation at the blastocyst stage of development. Blastocysts may either cease cell division so that their size and cell numbers remain constant， or undergo a period of very slow growth with minimal cell division. There are almost 100 mammalian species in seven different mammalian orders undergoing delayed implantation. Many factors are involved in regulating delayed implantation， including lactational stimulus， hormonal regulation， photoperiod and nutrition. Delayed implantation can effectively lengthen the gestation period， which allows mating to occur and young animals to be born at the optimal time.

CSTR: 32200.14.cjcb.2005.02.0009