Clarke Hugh J
Department of Obstetrics and Gynecology, McGill University, Montréal, QC, Canada.
Anim Reprod. 2018 Aug 16;15(3):215-223. doi: 10.21451/1984-3143-AR2018-0061.
Development and differentiation of a functional oocyte that following fertilization is able to give rise to a new individual requires continuous physical contact with the supporting somatic cells of the ovarian follicle. As the oocyte is surrounded by a thick extracellular coat, termed the , this essential contact is mediated through thin cytoplasmic filaments known as transzonal projections (TZPs) that project from the somatic granulosa cells adjacent to the oocyte and penetrate through the to reach the oocyte. Gap junctions assembled where the tips of the TZPs contact the oocyte plasma membrane, and other contact-dependent signaling may also occur at these sites. Here, I describe early studies of TZPs, which were first identified in the late 19th century, discuss their similarities with classical filopodia, review their structure and function, and compare two models that could account for their origin. Possible priorities and directions for future studies close this contribution.
一个功能性卵母细胞的发育和分化，使其在受精后能够产生一个新个体，这需要与卵巢卵泡的支持性体细胞持续进行物理接触。由于卵母细胞被一层厚厚的细胞外被包围，称为透明带，这种必要的接触是通过称为跨 zona 突起（TZPs）的细细胞质丝介导的，这些细丝从与卵母细胞相邻的体细胞颗粒细胞伸出并穿透透明带到达卵母细胞。缝隙连接在 TZPs 的尖端与卵母细胞质膜接触的地方组装，其他依赖接触的信号传导也可能在这些部位发生。在这里，我描述了 TZPs 的早期研究，它们在 19 世纪末首次被发现，讨论了它们与经典丝状伪足的相似性，回顾了它们的结构和功能，并比较了两种可以解释它们起源的模型。未来研究的可能重点和方向结束了这一贡献。
