Zouros Eleftherios, Rodakis George C
Department of Biology, University of Crete, Heraklion, Greece.
Department of Biology, National and Kapodistrian University of Athens, Athens, Greece.
Adv Anat Embryol Cell Biol. 2019;231:25-49. doi: 10.1007/102_2018_4.
We recount the basic observations about doubly uniparental inheritance (DUI) of mtDNA in bivalvian mollusks with an emphasis on those that were obtained from work in Mytilus and appeared after the review by Zouros (Evol Biol 40:1-31, 2013). Using this information, we present a new model about DUI that is a revised version of previously suggested models. The model can be summarized as follows. A Mytilus female either provides its eggs with the "masculinizing" factor S and the "sperm mitochondria binding" factor Z, or it does not. This property of the female is determined by two nuclear genes, S and Z, that are always in the on/on or the off/off phase. In fertilized eggs without factors S and Z the embryo develops into a female and the sperm mitochondria are randomly dispersed among cells following development. In fertilized eggs with factors S and Z, the first factor causes the cell to become eventually sperm and the second causes the sperm mitochondria to aggregate and anchor to the nuclear membrane by binding to a specific motif of the sperm-derived mtDNA. Factors S and Z are continuously co-synthesized and co-localized in the cell line from the egg to the sperm. The sperm mitochondria of the aggregate escape the mechanism that eliminates the cell's mitochondria before the formation of the sperm. The rescued mitochondria are subsequently packed into five mega-mitochondria in the sperm and are delivered in the egg.
我们详细叙述了双壳贝类线粒体DNA的双亲单亲遗传（DUI）的基本观察结果，重点关注那些来自贻贝研究且在Zouros（《进化生物学》40:1 - 31，2013年）的综述之后出现的结果。利用这些信息，我们提出了一个关于DUI的新模型，它是先前提出的模型的修订版。该模型可总结如下。一只贻贝雌性要么为其卵子提供“雄性化”因子S和“精子线粒体结合”因子Z，要么不提供。雌性的这种特性由两个核基因S和Z决定，它们总是处于开启/开启或关闭/关闭阶段。在没有因子S和Z的受精卵中，胚胎发育成雌性，精子线粒体在发育后随机分散在细胞中。在具有因子S和Z的受精卵中，第一个因子使细胞最终变成精子，第二个因子使精子线粒体通过与精子来源的线粒体DNA的特定基序结合而聚集并锚定到核膜上。因子S和Z在从卵子到精子的细胞系中持续共同合成并共定位。聚集的精子线粒体在精子形成之前逃脱消除细胞线粒体的机制。获救的线粒体随后在精子中被包装成五个巨型线粒体并传递到卵子中。
