The reproductive ACTIVITY is influenced by environmental conditions in most animal species. The aim of the present study was to determine the seasonal changes of seminiferous tubules structure and SPERMATOGENIC ACTIVITY in Khouzestan Arabian rams. For this propose 30 adult rams were reared under closed grazing conditions. Four rams were randomly selected in each season and their live weight, testicular weight and diameters were measured and recorded. Furthermore, their blood sera were collected for measuring testosterone by radioimmunoassay. For microscopic studies, the 5-6fl sections were made and stained with Haematoxylin - Eosin. Results showed that testicular weight and diameter were significantly changed by season (p<0.05) and the minimum values were seen in the beginning of summer. While spermatognic ACTIVITY was present in all seasons, structural changes were seen in seminiferous epithelium. The seminiferous tubule diameter and germinal epithelium height showed a gradual increase during different seasons during summer and autumn and the maximum values were seen in the beginning of winter. The maximum plasma testosterone was seen in the beginning of winter and significant decrease shown during spring (p<0.05). Seminiferous tubule diameter showed significant correlation with testicular diameter and testosterone levels. It can be concluded that SPERMATOGENIC ACTIVITY of seminiferous tubules in adult khouzestan Arabian rams are highly affected by season.

Background: Infertility affects 15% of couples around the world. Male factor accounts for 40-50% of conjugal infertility. cAMP responsive element modulator (CREM) is a key factor in the regulation of the expression of number of postmeiotic genes that control spermatogenesis. Aloe vera is a medicinal plant used to treat several diseases. The purpose of this study was to investigate effects of Aloe vera extract on rat spermatogenesis with emphasis on sperm parameters, hormonal assay, and CREM gene expression in testis tissue. Materials and Methods: Aloe vera leaf pulp extract, gel extract, and a mixture of both administered to three groups of 10-week old male Wistar rats for 56 consecutive days. Then sperm analysis, hormonal assay, and RT-PCR were carried out.Results: Results indicated that in all groups except control group the weights of the testes have increased. Epididymal sperm counts and sperm motility have been increased significantly compared to control groups. Analysis of testosterone level between groups showed that the level of this hormone in the groups that treated with Aloe Vera has increased remarkably. Results of RTPCR showed an increase in the CREM gene expression in the groups that received gel extract and mixture of gel and leaf pulp extract. Conclusion: According to the results of this study, Aloe Vera has strong SPERMATOGENIC ACTIVITY by increasing sperm parameters and CREM gene expression. This study strongly proposes that Aloe vera specially its gel fortifies spermatogenesis and can be a good candidate for manufacturing fertility drugs.