| The testicular microstructures of Rana chensinensis in Qinling Mountains were oberserved using histological methods during the annual reproductive cycle, referring to the variations of testis somatic index, in an attempte to investigate its reproductive rule. To elucidate the relationships among testosterone (T), l?p-estradiol (E3), progesterone (P), their receptors and spermatogenesis, the localization of steroid hormone and their receptors has been studied by immunocytochemistry in the testis. Fos Jun, and Myc protein immunoreactivity localization was investigated to discuss regulation mechanism of spermatogenesis. At the same time, morphological variations and immunocytochemistry localization of T and androgen receptor (AR) in the nuptial pad were oberserved to correlate variations of nuptial pad microstructures and testis somatic index with spermatogenesis during annual reproductive cycle in this species.1. The spermatogenetic cycle of Rana chensinensis in Qinling Mountains is of discontinuous type. The seasonal variation of testis somatic index showed a good agreement with the spermatogenetic cycle. The spermatogenesis in Rana chensinensis commonly starts in May and end in April next year, which takes one year from spermatogonial proliferation to spermiation.2. The spermatogenetic cycle of Rana chensinensis in Qinling Mountains comprises five stages with significant features: Stage I from May to July, testis somatic index in minimum, mitotic proliferation of spermatogonia, other spermatogenic cells didn't come into being; Stage II from August to September, testis somatic index in maximum, many spermatogonia, spermatocytes and spermatids were observed in seminiferous tubules; Stage III from September to October, spermatids were transformed to spermatozoa; Stage IV from November to February,mature spermatozoa stored in seminiferous tubules; StageV from March to May, the testis somatic index appeared significant decline, mature spermatozoa were released from sertoli cell into the tubule lumen, thereafter were evacuated from the testis.3. T and AR have been found have uique immunoreactivity localization in the testis of Rana chensinensis in Qinling Mountains. Through binding to AR, T acts on maintenance of spermatogonia activity and proliferation potential, promotesspermatocytes meiosis, and is involved in spermioteleosis and maintenance of spermatozoa activity. During courtship, elevating T level may play a major role in inducing Sertoli cells and spermatozoa to be detached from basement membrane, and promoting spermiation. T produced by Leydig cells regulates Leydig cell activity in an autocrine fashion, and has paracrine effects on steroidogenesis of Sertoli cells, accordingly regulats spermatogenesis.4. Ea exerts regulation role through estrogen receptor (ER) localized in spermatogenic cells, including stimulating spermatogonia multiplication, preventing spermatogenic cells apoptosis and maintaining spermatogonia activity. ? plays a role in the recrudescence of spermatogenesis after hibernation. ? regulates spermatogenesis of Leydig and Sertoli cells in autocrine and paracrine fashions to maintain proper steroid hormone concentration. Besides Leydig and Sertoli cells, spermatogenic cells may also synthesize E2.5. P and progesterone receptor (PR) probably exert role in spermatogenesis regulation by genomic pathway. P may be concerned with transformation of spermatids and spermatozoa maturation. Besides Leydig cells, spermatogenic cells may synthesize P.6. Proto-oncogenes c-fos, c-jun and c-myc regulate spermatogenesis of Rana chensinensis in Qinling Mountains, and probably are related to regulation of steroidogenesis. Fos, Jun and Myc distributed in spermatogonia, spermatocytes and spermatids with different immunoreactivity, but Myc presented negative reaction in spermatozoa and Leydig cells. AP-1 complexes transform to spermatogonia nucleus to initiate spermatogenesis. High density Jun in spermatids may be related to spermatids apo...
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