Teleost Oogenesis and Oocyte Growth

本研究中研究的生殖细胞发育的两个主要方面 建议是：a）卵子发生本身（卵原细胞的转化 进入卵母细胞）和早期卵母细胞发育和B）启动 卵黄发生尖嘴鱼，海龙， 海马，直立海马，将被使用，因为 卵巢中发育卵泡的独特排列， 其中观察到卵母细胞发育的顺序模式。 这种模式开始于卵巢的一侧， 发育年龄增加的卵泡向相反方向延伸 的方面想关于早期事件的调节知之甚少， 大多数脊椎动物胚胎卵巢中的卵母细胞形成， 在许多情况下，成年卵巢中缺乏非常早期的卵母细胞， 物种存在的萌发组织（卵原细胞和减数分裂 卵母细胞）在一个有限的，但容易接近的区域， 海龙的卵巢使这些硬骨鱼成为早期研究的理想对象 成人生殖细胞事件及其激素调节 脊椎动物卵原细胞增殖的程度和时间 卵母细胞通过减数分裂的进展将在 vivo.然后，塞尔曼博士将尝试在 通过检测各种激素和共刺激物对体外细胞增殖的影响， 培养组织对卵原细胞分裂和 从细线期到双线期的卵母细胞。的过程 还将检查卵泡形成。塞尔曼博士打算 描述了从卵黄发生前到 海龙类的卵黄发生， 负责启动卵黄发生的机制。 为此，她将检查卵泡血管化， 卵黄蛋白原可及性，功能性卵黄蛋白原的个体发育， 卵黄蛋白原受体和内化的卵黄蛋白在卵细胞内的命运 卵黄蛋白原将在体内和体外进行研究 以确定正常溶酶体合成的停止是否 和/或内吞途径的活性或修饰 区分卵黄发生前和卵黄发生卵母细胞。

The two major aspects of germ cell development examined in this proposal are: a) oogenesis per se (the transformation of oogonia into oocytes) and early oocyte development and b) the initiation of vitellogenesis. Both the pipefish, Syngnathus scovelli, and the seahorse, Hippocampus erectus, will be used because of the unique arrangement of developing follicles in their ovaries, where a sequential pattern of oocyte development is observed. This pattern begins on one side of the ovary and a gradient of follicles of increasing developmental age extends to the opposite side. Little is known about the regulation of early events of oocyte formation in embryonic ovaries of most vertebrates and the absence of very early stage oocytes in adult ovaries in many species. The presence of germinal tissue (oogonia and meiotic oocytes) in a restricted but easily accessible region of syngnathan ovaries makes these teleost ideal for studying early germ cell events and their hormonal regulation in an adult vertebrate. The extent of oogonial proliferation and the time for progression of oocytes through meiosis will be determined in vivo. Dr. Selman will then attempt to duplicate both processes in vitro by examining the influence of various hormones and co- cultured tissues on oogonial division and the progression of oocytes from leptotene up to diplotene stages. The process of follicle formation will also be examined. Dr. Selman intends to characterize the transition from previtellogenesis to vitellogenesis in syngnathans and will address the cellular mechanism(s) responsible for the initiation of vitellogenesis. For this she will examine follicular vascularization, vitellogenin accessibility, the ontogeny of functional vitellogenin rectors and the intraoocytic fate of internalized vitellogenin. Studies will be performed both in vivo and in vitro to determine whether a cessation of normal lysosomal synthesis and/or activity or a modification of the endocytic pathway distinguishes previtellogenic form vitellogenic oocytes.