SummaryGerm plasm, a cytoplasmic factor of germline cell differentiation, is suggested to be a perspective tool for in vitro meiotic differentiation. To discriminate between the: (1) germ plasm-related structures (GPRS) involved in meiosis triggering; and (2) GPRS involved in the germ plasm storage phase, we investigated gametogenesis in the marine medaka Oryzias melastigma. The GPRS of the mitosis-to-meiosis period are similar in males and females. In both sexes, five events typically occur: (1) turning of the primary Vasa-positive germ plasm granules into the Vasa-positive intermitochondrial cement (IMC); (2) aggregation of some mitochondria by IMC followed by arising of mitochondrial clusters; (3) intramitochondrial localization of IMC-originated Vasa; followed by (4) mitochondrial cluster degradation; and (5) intranuclear localization of Vasa followed by this protein entering the nuclei (gonial cells) and synaptonemal complexes (zygotene–pachytene meiotic cells). In post-zygotene/pachytene gametogenesis, the GPRS are sex specific; the Vasa-positive chromatoid bodies are found during spermatogenesis, but oogenesis is characterized by secondary arising of Vasa-positive germ plasm granules followed by secondary formation and degradation of mitochondrial clusters. A complex type of germ plasm generation, ‘the follicle cell assigned germ plasm formation’, was found in late oogenesis. The mechanisms discovered are recommended to be taken into account for possible reconstruction of those under in vitro conditions.

中文翻译：

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海洋青鳉配子发生中的种质相关结构；Vasa定位的新位点和种质颗粒产生的独特机制

摘要生殖质是种系细胞分化的细胞质因子，被认为是一种透视工具体外减数分裂分化。区分：（1）参与减数分裂触发的种质相关结构（GPRS）；(2) GPRS 参与种质储存阶段，我们研究了海洋青鳉的配子发生黄褐斑稻. 有丝分裂到减数分裂时期的 GPRS 在男性和女性中是相似的。在两性中，通常会发生五种事件：（1）初级 Vasa 阳性种质颗粒转变为 Vasa 阳性线粒体间水泥（IMC）；(2) 一些线粒体通过 IMC 聚集，随后出现线粒体簇；(3) IMC 起源 Vasa 的线粒体内定位；其次是（4）线粒体簇降解；(5) Vasa 的核内定位，随后该蛋白质进入细胞核（生殖细胞）和联会复合体（合子-粗线期减数分裂细胞）。在后合子/粗线期配子发生中，GPRS 是性别特异性的；在精子发生过程中发现 Vasa 阳性染色质体，但卵子发生的特征是继发于 Vasa 阳性种质颗粒，然后继发于线粒体簇的形成和降解。在卵子发生晚期发现了一种复杂的种质生成类型，即“卵泡细胞指定的种质形成”。建议将发现的机制考虑在内，以便可能重建以下机制体外状况。