近日，德国马克斯-普朗克多学科科学研究所Melina Schuh及其课题组发现，哺乳动物的卵母细胞在线粒体相关的无膜区间内储存mRNA。2022年10月21日出版的《科学》杂志发表了这项成果。

研究人员发现，哺乳动物的卵母细胞在线粒体相关的核糖核蛋白域（MARDO）中积累mRNA。MARDO在线粒体周围的组装是由RNA结合蛋白ZAR1促进的，并且在卵母细胞生长过程中由线粒体膜电位的增加引导。MARDO点凝聚成水凝胶状基质，将线粒体聚集起来。储存在MARDO中的母体mRNA被翻译抑制。ZAR1的丢失破坏了MARDO，分散了线粒体，并导致MARDO定位的mRNA过早丢失。因此，一个与线粒体相关的无膜区室控制线粒体的分布，并调节母体mRNA的储存、翻译和降解，从而确保哺乳动物的生育能力。

据介绍，成熟的卵母细胞在转录上是沉默的，必须稳定地维持卵母细胞减数分裂成熟和早期胚胎发育所需的mRNA。然而，哺乳动物的卵母细胞在哪里以及如何储存母体mRNA尚不清楚。

附：英文原文

Title: Mammalian oocytes store mRNAs in a mitochondria-associated membraneless compartment

Author: Shiya Cheng, Gerrit Altmeppen, Chun So, Luisa M. Welp, Sarah Penir, Torben Ruhwedel, Katerina Menelaou, Katarina Harasimov, Alexandra Stützer, Martyn Blayney, Kay Elder, Wiebke Mbius, Henning Urlaub, Melina Schuh

Issue&Volume: 2022-10-21

Abstract: Full-grown oocytes are transcriptionally silent and must stably maintain the messenger RNAs (mRNAs) needed for oocyte meiotic maturation and early embryonic development. However, where and how mammalian oocytes store maternal mRNAs is unclear. Here, we report that mammalian oocytes accumulate mRNAs in a mitochondria-associated ribonucleoprotein domain (MARDO). MARDO assembly around mitochondria was promoted by the RNA-binding protein ZAR1 and directed by an increase in mitochondrial membrane potential during oocyte growth. MARDO foci coalesced into hydrogel-like matrices that clustered mitochondria. Maternal mRNAs stored in the MARDO were translationally repressed. Loss of ZAR1 disrupted the MARDO, dispersed mitochondria, and caused a premature loss of MARDO-localized mRNAs. Thus, a mitochondria-associated membraneless compartment controls mitochondrial distribution and regulates maternal mRNA storage, translation, and decay to ensure fertility in mammals.

DOI: abq4835

Source: https://www.science.org/doi/10.1126/science.abq4835