Expression Of NGF, BDNF, NT-4/5 In The Reproductive Organs In Female Buffalo

According to the statistics, China has the third largest population of buffalo in the world which have made tremendous social and economic value. However, there is a bottle neck of buffalo raising in China because of the low reproductive rate and poor productive characters of buffalo, including seasonal estrus, silent estrus, not obvious expression of estrus, long calving interval. Therefore. advantaged techniques are desperately needed for the improvement.Nerve growth factor (NGF), Brain-derived neurotrophic factor(BDNF) and Neutrophin-4/ 5(NT-4/5) are the three important members of the family of neurotrophic factors, which play important roles in growth, conservation, and restoration of nerve cells. In recent years, studies in women and mouse have shown that NGF,BDNF and NT-4/5 were also expressed in the ovaries and might affect the development and maturation of oocytes. when blocking the binding of NGF,BDNF andNT-4/5 to their receptors with the receptor inhibitors, the development of ovaries of female animals.oocyte maturation and early embryonic development were hindered. The development of ovaries is severly disturbed in the KO mouse model when single neurotropin (NGF,BDNF,NT4-5) or its receptor gene is knocked-out.In view of the potentially important role of the neurotrophic factors in reproductive control of female mammals,we chose adult female buffalos from Guangxi as subjects, using methods of immunohistochemistry and fluorescence quantitative PCR to determine the expression levels of mRNA for NGF, BDNF, NT-4/5 in reproductive organs in female buffalo as well as studying the regulatory mechanisms of neurotrophic factors in different stages of estrus cycle activity in female buffalo from the molecular level, provided evidences for the further study of the buffalo reproductive endocrinology and reproduction improvement.The main results are as followeds: 1. The expression sites of NGF, BDNF, NT-4/5 proteins in buffalo reproductive organs.The expression sites of NGF, BDNF,NT-4/5 in ovaries, oviducts and uterus from buffalos were located by using immunohistochemisty, the result illustrated that the expression of the NGF, BDNF.NT-4/5 at different stages of the estrous cycle (follicular/luteal phase) of the ovary, uterus and oviduct were distributed in different parts of the reproductive organs, including the follicle cells.ovarian granulosa cells and inner theca cells, luteal cells, endometrial epithelial cells, uterine gland cells and oviduct columnar epithelial cells.2. The expression levels of mRNAs for NGF, BDNF, NT-4/5 in buffalo reproductive organs.The expression levels of mRNA for NGF, BDNF, NT-4/5 in ovaries, oviducts, and uterus from sows at follicular phase and luteal phase were quantitated by using Real-time Fluorescent Quantitative Polymerase Chain Reaction (RT-FQ-PCR). The results showed that mRNAs for NGF, BDNF, NT-4/5 were expressed in all of the tissues at each phase. The expression levels of mRNAs for NGF, BDNF, NT-4/5 in luteal phase ovary and oviduct trended to be higher than those in follicular phase. However, the expressions in uterus were opposite to that, ie, higher levels of mRNA were found in follicular phase than in luteal phase. When the buffalo is in the luteal phase of estrous cycle stage, the expression level of mRNA for NGF in ovaries were the highest, followed by the uterus, oviducts were the minimum; the expression level of mRNAs for BDNF and NT-4/5 in oviducts at this stage were higher compared with uterus and ovaries. When the buffalo in the follicular phase, all the expression levels of mRNAs for NGF, BDNF, NT-4/5 were the highest in uterus, followed by ovaries, and the oviducts were the lowest.In summary, this study demonstrated that NGF, BDNF, NT-4/5 mRNAs and proteins were expressed in reproductive organs (ovaries, uterus, oviducts) of the female buffalo, exhibiting cyclical changes during the estrous cycle. This study not only provide a theoretical basis to the reproductive physiology of buffalo, but also reveal the biological function and mechanism of neurotrophic factors in mammalian reproductive activities.