2006-08-012024-05-18https://scholars.lib.ntu.edu.tw/handle/123456789/698498摘要：雖然精原幹細胞可一直一邊複製自己,一邊分化提供成熟的精蟲,大部分哺乳動物的卵子被認為是在初生時數目就已被決定,亦即沒有可複製自己的生殖幹細胞的存在.但是最近一篇研究報告提供很明確的證據,顯示有一邊複製自己,一邊分化提供成熟卵子的卵生殖幹細胞的存在.因此探尋研究維持這類卵生殖幹細胞所須的分子及其作用機制是此研究計劃的主要目標. 基於以下陳述之原因,我們選定Plzf及Fig{alpha}作為此研究之分子. Plzf 是屬於POK家族的轉錄因子,也是目前所知唯一屬於精原生殖幹細胞內自生性分子,且是維持精原幹細胞自生及分化性質所必需之分子.Fig{alpha}是bHLH轉錄因子,特定存在於陰性生殖細胞內,它已知功能是對形成最早濾泡有決定性的影響.但是我們完全不知它們對卵子幹細胞的影響為何.因此詳細的研究,例如這些基因在卵子發育過程中表現情形,失去它們時對卵生殖幹細胞的影響及這些分子作用的對像等,將會對了解卵生殖幹細胞是如何維持,及哺乳動物生殖系統如何發育有極大的幫助. <br> Abstract: Although males retain germline stem cells for spermatogenesis throughout adult life, oocyte production in most mammalian females is believed to cease before birth. Accordingly, a doctrine of mammalian reproductive biology is that females are born with a finite, non-renewing pool of germ cells enclosed by somatic cells in structures referred to as follicles. Nevertheless, recently it was convincingly demonstrated that, contrary to long-held views, female mice contain a population of germline stem cells that are required to maintain overall follicle numbers during adult life. Seeking the factor(s) and thereby the molecular mechanisms that maintain the female germline stem cells are the aims of this proposed study. Two molecules, Plzf and Fig{alpha} are chosen for this study based on the following reasons. Plzf (promyelocytic leukemia zinc-finger) belongs to the POK (POZ and Kr&uuml;ppel) family of transcriptional repressors. By far it is the only known example of a cell-autonomous germ cell factor required for spermatogonial stem cell maintenance. Fig{alpha} is a bHLH transcription factor, present specifically in the female germ cells, and is known to be critical for the formation of primordial follicles. Nothing is known on their roles in maintaining female germline stem cells. Therefore, detailed studies on the expression profiles corroborated with the effects of lost-of-function of these three genes in ovaries of embryos and postnatal mice, as described in the following section should provide useful molecular information on enhancing the understanding of the maintenance of female germline stem cells and the development of the mammalian reproductive system.卵生殖幹細胞轉錄因子.Female germline stem cellsTranscription factors.