Molecular mechanisms of embryonic diapause in fruit bat Cynopterus sphinx role of Prolactin Adiponectin Kisspeptin and Putrescine

Abstract

One of the most intriguing phenomena in reproductive biology is the reversible newlinearrest of embryonic development known as delayed embryonic development or newlineembryonic diapauses. An embryo is in diapause when its rate of cell division is newlinedecreased or has completely stopped and development begins again when active newlinemitotic activity reoccurs. Delayed development is characterized by slow or arrested newlineperi-implantational blastocyst, reduced or ceased cell proliferation or migration and newlinethere is down regulation of metabolism. There is a complex interplay of many stimuli newlinewhich regulate the entrance and exit from delayed embryonic development. The newlinephysiological and evolutionary significance of embryonic diapauses provides a newlinewonderful system for understanding the reproductive endocrinology and control of newlineearly embryonic development in mammals. However, the molecular and biochemical newlinemechanism involved in this intriguing phenomenon are not well understood. newlineThe present dissertation is based on earlier studies from this laboratory, demonstrating newlinedifferential gestation length in Cynopterus sphinx in two successive pregnancies of the newlineyear at Varanasi, India. Based on this study, it was demonstrated that the differential newlinegestation length in Cynopterus sphinx is because of delayed embryonic development newlineduring early stage of gastrulation of first pregnancy (October to March). Further studies newlinefrom our laboratory suggested that increase abdominal fat accumulation may be the newlineprimary factor responsible for the delayed embryonic development in Cynopterus newlinesphinx during winter dormancy (November-December). Although it is well newlinedocumented that the obese women experience impaired fertility; however, the newlinemechanism which links obesity to reduced fertility remains to be fully elucidated. newlineEarlier study showed that a significant increase in the circulating melatonin level newlineprovides the cue for initiation of fat deposition.