부산대학교 도서관

The only few follicles are destined to ovulate after the precise cellular interactions during the folliculogenesis in mammals. It remains that the immunohistochemical studies concerning the expressions of the various proteins participating in the cell-cycle progression, the control of the transcription during the cellular signaling cascade, the repair of the damaged DNA, and the regulation of the secretion of the gonadotropins by negative feedback mechanisms to be solved. In the present study, the immunohistochemical expressions of proliferating cell nuclear antigen (PCNA), signal transducers and activator of transcription-3 (STAT-3), inhibin-α, and deoxyribonucleic acid-protein catalytic subunit (DNA-PKcs) were identified during the transition stage of primordial germ cells to the primordial follicles and the growth initiating stage using fetal and neonatal mice ovaries. The present study was extended to know the changes of the expressions of these proteins according the follicle development. The ovaries were obtained at 14 and 16 days post coitum (dpc), 1, 2 and 7 days post partum (dpp) in ICR strain mice. Using the routine histochemical preparations, the tissue sections were prepared and stained with hematoxylin and eosin for the observation of the histologic changes. The Immunohistochemical localizations in the serial sections for STAT-3, PCNA, DNA-PKcs, and inhibin-α were carried out using the respective primary antibodies. The shapes of the germ cells were round and larger than the somatic ones at 14 dpc. The oogonia were distributed at medulla and cortex regions 16 dpc. At the neonatal stages, the developments of the primordial follicles were observed in the medulla region. More developed follicles were observed 7 dpp and in the cortical region, primordial follicles were mainly observed. It was shown that the developed follicles were more existed in the medullar region, PCNA was immunolocalized on the oogonia and granulosa cells of the fetal and neonatal ovarian follicles, respectively. The expression of PCNA was decreased in the atretic follicles. Its ovarian expression was strong in the medulla where the germ cells were concentrated, but weak in the somatic cells in case of 14 dpc. The immunohistochemical expressions of STAT-3 proteins were identified around the oogonia at 14 dpc and the localities of the expression were on the nuclei and cytoplasms of the oocytes. At the neonatal stage, STAT-3 proteins were expressed on the oocytes. During the immature stage, STAT-3 proteins were expressed in nuclei and cytoplasms of primary follicles, but there expressions were weak in oocytes and cytoplasms of granulosa cells of growing follicles. In case of the expression of DNA-PKcs, it was detected in oogonia during fetal stages, and oocytes and granulosa cells, except thecal layers, during the neonatal stages. At 2 days after birth, the expression of DNA-PKcs was decreased in oocytes, and increased in granulosa cells. At 7 days after birth, it was identified in oocytes of primordial follicles. The expression of inhibin-α proteins were observed in the granulosa cells of primary, 2 or 3 layered secondary follicles. In addition, it was identified in preantral and early antral follicular granulosa cells. However, in case of atretic follicles, its expression was weak. Above results, suggest that expressions of STAT-3, PCNA, DNA-PKcs, and inhibin-α are different from the stages of the ovarian development and the growth stages of the ovarian follicles in mice. Taken together, it is thought that further elucidation of the exact changes of the expressions of the various cell cycle-related and the growth control proteins and the precise molecular action mechanisms of these proteins in the folliculogenesis are to be needed.