1. Provincial Key Laboratory for Developmental Biology and Neurosciences; Key Laboratory of OptoElectronic Science and Technology for Medicine of Ministry of Education; College of Life Sciences; Fujian Normal University; No. 8, Shangsan Road Fuzhou 350007 P. R. China
2. Department of Obstetrics and Gynecology; The First Affiliated Hospital of Fujian Medical University; Fuzhou 350005 P. R. China