Johns Hopkins University, Baltimore, MD, U.S.A.
Biochem J. 2022 Dec 19;479(24):2477-2495. doi: 10.1042/BCJ20210815.
Reproductive success of metazoans relies on germ cells. These cells develop early during embryogenesis, divide and undergo meiosis in the adult to make sperm and oocytes. Unlike somatic cells, germ cells are immortal and transfer their genetic material to new generations. They are also totipotent, as they differentiate into different somatic cell types. The maintenance of immortality and totipotency of germ cells depends on extensive post-transcriptional and post-translational regulation coupled with epigenetic remodeling, processes that begin with the onset of embryogenesis [1, 2]. At the heart of this regulation lie germ granules, membraneless ribonucleoprotein condensates that are specific to the germline cytoplasm called the germ plasm. They are a hallmark of all germ cells and contain several proteins and RNAs that are conserved across species. Interestingly, germ granules are often structured and tend to change through development. In this review, we describe how the structure of germ granules becomes established and discuss possible functional outcomes these structures have during development.
后生动物的生殖成功依赖于生殖细胞。这些细胞在胚胎发生早期发育,在成年期分裂并经历减数分裂,以产生精子和卵子。与体细胞不同,生殖细胞是不朽的,并将其遗传物质传递给新的世代。它们也是全能的,因为它们可以分化为不同的体细胞类型。生殖细胞的不朽性和全能性的维持取决于广泛的转录后和翻译后调节,以及与表观遗传重塑相关的过程,这些过程始于胚胎发生的开始[1,2]。这种调节的核心是生殖颗粒,这是一种无膜的核糖核蛋白凝聚物,专门存在于生殖细胞质中,称为生殖质。它们是所有生殖细胞的标志,包含几种在物种间保守的蛋白质和 RNA。有趣的是,生殖颗粒通常具有结构,并在发育过程中发生变化。在这篇综述中,我们描述了生殖颗粒的结构是如何建立的,并讨论了这些结构在发育过程中可能具有的功能结果。