Molecular and cellular aspects of blastocyst dormancy and reactivation for implantation

Blastocyst activation, a process for the blastocyst to achieve implantation competency is equally important as attainment of uterine receptivity for the success of embryo implantation. While a wide range of regulatory molecules have been identified as essential players in conferring uterine receptivity in both laboratory animal models and humans, it remains largely unknown how blastocysts achieve implantation competency. This chapter will highlight our current knowledge about the mechanisms governing the process of blastocyst activation. A better understanding of this periimplantation event is hoped to alleviate female infertility and help to develop novel contraceptives and new strategies for accessing embryo quality in clinical practice.