Expression Of Nerve Growth Factor And Its Recptors In Ovary Of Wild Ground Squirrel

Seasonal breeding is a kind of special reproductive mode which is suitable for the wild environment, it is common in the wildlife rather than experimental animals. The wild ground squirrel (Citellus dauricus Brandt), a wide spread rodent, is an ideal model for study the seasonal breeding mechanism.Nerve growth factor (NGF) and its receptors is a kind of wide spread proteins, required for the survival, maintenance and development of the nervous, endocrine and reproductive systems. In female reproductive system, NGF actives its role in paracrine and autocrine mechanism, which stimulating the growth of follicles, ovulation and steroid regulation.In this study, we used histological observation, immunohistochemistry, Western blotting and RT-PCR to check the protein and mRNA level of NGF and its receptors during different periods. The results showed that there were remarkable reductions in ovarian weights and sizes from breeding period to non-breeding period. Immunolocalization for NGF and its receptors was observed in granulose cell, thecal cell, intersitial cell and luteal cell in breeding season, but in non-breeding period, only granulose cell, thecal cell and interstitial cell was localized and expression level was down. Corresponding for the immunohistochemistry, the expressive level of Western blotting and RT-PCR are decreased from breeding period to non-breeding period. In conclusion, the results showed that, in breeding period, NGF and its receptors expressed higher level than non-breeding period. In the term of follicular development, NGF and its receptors play an important regulative role from primordial follicles to mature follicles.