Department of Animal Science, Okayama University, Okayama, Japan; Department of Animal Reproduction, INIA-CSIC, Madrid, Spain; Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden.
Department of Animal Reproduction, INIA-CSIC, Madrid, Spain.
Theriogenology. 2023 Jul 15;205:87-93. doi: 10.1016/j.theriogenology.2023.04.009. Epub 2023 Apr 18.
Mammalian follicles are constituted of a complex structure composed of several layers of granulosa cells surrounding the oocyte and of theca cells that reside beneath its basement membrane. During folliculogenesis, granulosa cells separate into two anatomically and functionally distinct sub-types; the mural cells lining the follicle wall and the oocyte-surrounding cumulus cells, i.e. those in intimate metabolic contact with the oocyte. The cumulus cells connecting with the oocyte have trans-zonal cytoplasmic projections which, penetrating the zona pellucida, form the cumulus-oocyte complex. The connections through gap junctions allow the transfer of small molecules between oocyte and cumulus cells, such as ions, metabolites, and amino acids necessary for oocyte growth, as well as small regulatory molecules that control oocyte development. The bi-directional communication between the oocyte and cumulus cells is crucial for the development and functions of both cell types. Our current knowledge of the relationship between the oocyte and its surrounding cumulus cells continues to change as we gain a greater understanding of factors regulating oocyte development and folliculogenesis. This review will mainly focus on the reciprocal interaction between oocytes and cumulus cells during the latter stages of follicle development i.e. through antral development to periovulatory events including oocyte maturation, expansion, and degradation of the cumulus matrix.
哺乳动物的卵泡由多层颗粒细胞围绕卵母细胞和位于其基底膜下的膜细胞组成，构成一个复杂的结构。在卵泡发生过程中，颗粒细胞分为两种解剖和功能上明显不同的亚型；卵泡壁的壁细胞和卵母细胞周围的卵丘细胞，即与卵母细胞密切代谢接触的细胞。与卵母细胞相连的卵丘细胞具有穿过透明带的跨带细胞质突起，形成卵丘-卵母细胞复合体。通过缝隙连接实现卵母细胞和卵丘细胞之间小分子的转移，如离子、代谢物和氨基酸等，这些物质是卵母细胞生长所必需的，还有一些小的调节分子控制卵母细胞的发育。卵母细胞和卵丘细胞之间的双向通讯对于两种细胞类型的发育和功能都至关重要。随着我们对调节卵母细胞发育和卵泡发生的因素有了更深入的了解，我们对卵母细胞与其周围卵丘细胞之间关系的认识也在不断变化。本篇综述主要关注卵泡发育后期即从窦前发育到排卵前事件期间卵母细胞和卵丘细胞之间的相互作用，包括卵母细胞成熟、扩张和卵丘基质的降解。
