美国霍华德·休斯医学研究所Allan C. Spradling团队发现,小鼠卵母细胞在哺育细胞的帮助下在囊中发育。相关论文于2022年5月26日在线发表在《细胞》杂志上。
研究人员表明,在E14.5和P5之间,囊周期性地激活一些营养细胞,开始细胞质转移,这导致它们在2天内收缩和周转。哺育细胞通过涉及酸化的程序性细胞死亡(PCD)途径死亡,与果蝇的哺育细胞类似,只有少数情况下通过凋亡死亡。在开始转移之前,通过scRNA-seq发现,哺育细胞与它们的原卵母细胞姐妹共同聚集,但在它们的最后2天,它们单独聚集。
促进卵细胞发育和哺育细胞PCD的基因被上调,而抑制转移的基因,如Tex14,和卵细胞因子,如Nobox和Lhx8,则表达不足。转移的哺育细胞中心体建立了一个细胞中心体,这在原始卵细胞中建立了一个大的微管群,而这又组织了巴尔比尼体,从而定义了最早的卵细胞极性。
据悉,小鼠生殖囊平均发育成6个卵母细胞,由24个哺育细胞支持,这些细胞转移细胞质和细胞器以生成巴尔比尼体。
附:英文原文
Title: Mouse oocytes develop in cysts with the help of nurse cells
Author: Wanbao Niu, Allan C. Spradling
Issue&Volume: 2022-05-26
Abstract: Mouse germline cysts, on average, develop into six oocytes supported by 24 nurse cells that transfer cytoplasm and organelles to generate a Balbiani body. We showed that between E14.5 and P5, cysts periodically activate some nurse cells to begin cytoplasmic transfer, which causes them to shrink and turnover within 2 days. Nurse cells die by a programmed cell death (PCD) pathway involving acidification, similar to Drosophila nurse cells, and only infrequently by apoptosis. Prior to initiating transfer, nurse cells co-cluster by scRNA-seq with their pro-oocyte sisters, but during their final 2 days, they cluster separately. The genes promoting oocyte development and nurse cell PCD are upregulated, whereas the genes that repress transfer, such as Tex14, and oocyte factors, such as Nobox and Lhx8, are under-expressed. The transferred nurse cell centrosomes build a cytocentrum that establishes a large microtubule aster in the primordial oocyte that organizes the Balbiani body, defining the earliest oocyte polarity.
DOI: 10.1016/j.cell.2022.05.001
Source: https://www.cell.com/cell/fulltext/S0092-8674(22)00579-7