| The reproductive cycle of female animals is regulated by the complicated mechanisms including circulatory regulation through hypothalamus-pituitary-gonadal axis and local regulation in ovaries. Lots of cytokines or growth factors are documented in regulating the development and function of female reproductive tissues. Neuotrophic factor NT-4/5 plays an important role in growth, development, and restoration of nerve cells, which is a member of the neurotrophic factors. In recent years, studies in women and mouse have shown that NT-4/5 were also expressed in the ovaries and might affect the development and maturation of the oocytes. These findings make the NT-4/5 as a new member of growth factors involved in regulation of reproduction process.There were three purposes in the present study: First was to determine the expression locations of the NT-4/5 in the reproductive organs from prepubertal gilts; Second was to determine the mRNA expression of NT-4/5 in reproductive organs at follicular phase and luteal phase from sows; Third was to investigate the expression levels of the NT-4/5 mRNA in the reproductive organs, under a short-term treatment with different levels of dietary energy intake in prepubertal gilts.The expression location of the NT-4/5 in ovaries, oviducts, and uterus from prepubertal gilts were located by using immunohistochemistry. The result showed that NT-4/5 expressed in the granular cell of ovary, which was consistent with the precious study of the TrkB; In the uterus and oviducts it was expressed in the epithelium mucosae cells.The expression levels of mRNA for 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 mRNA of the NT-4/5 was expressed in all of the tissues at each phase. The expression level in follicular phase ovary trended to be higher than that in luteal phase ovary, implying that NT-4/5 may effect the growth of follicles; In the oviduct, the expression levels of the NT-4/5 were higher in the luteal phase ovary than that in the follicular phase ovary, indicating that NT-4/5 may be important to the fertility and development of the zygote. However, the expression in uterus were opposite to that, higher level of mRNA of NT-4/5 were found in follicular phase than in luteal phase. When in the same phase ,we found that in luteal phase, NT-4/5 expressed more in oviduct than in ovary and uterus (P<0.05); in follicular phase, the expression level of NT-4/5 in the uterus was higher than that in the oviduct and ovary (P<0.05). These results implied that NT-4/5 may play different roles in luteal formation, sperm capacitation, fertilization, and early embryo development.RT-FQ-PCR was also used to determine the Effects of Dietary Energy Levels on the expression of NT-4/5 in reproductive organs. we found that the level of NT-4/5 in high energy group were higher than that of the low energy group, the effects of dietary energy levels on the expression of NT-4/5 in oviduct was more obvious than in the other two tissues. Maybe it becauses the oviduct was more sensitive to the dietary energy. At the same energy group, the comparison between the three tissues are as follows: In high-energy group, expression levels of NT-4/5 on fallopian tube was the highest , however uterine was the lowest, the differences between them were extremely significant (P<0.01); In the middle-group, the expression of NT-4 / 5 in the three tissues was similar; In the low-energy group, the ovarian expressed highest, followed by uterine, fallopian tube expressed the minimum, but the differences between them were not significant(P>0.05). The present study provides the molecular basis for the reproductive performance affected by energy intake。... |
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