Venetis Constantinos, Theologidis Ioannis, Zouros Eleftherios, Rodakis George C
Department of Biochemistry and Molecular Biology, National and Kapodistrian University of Athens, Panepistimioupolis, 15701 Athens, Greece.
Proc Biol Sci. 2006 Oct 7;273(1600):2483-9. doi: 10.1098/rspb.2006.3607.
Species of the mussel family Mytilidae have a special mitochondrial DNA (mtDNA) transmission system, known as doubly uniparental inheritance (DUI), which consists of a maternally inherited (F) and a paternally inherited (M) mitochondrial genome. Females are normally homoplasmic for the F genome and males are heteroplasmic mosaics, with their somatic tissues dominated by the maternal and their gonads dominated by the paternal genome. Several studies have indicated that the maternal genome may often be present in the male germ line. Here we report the results from the examination of mtDNA in pure sperm from more than 30 males of Mytilus galloprovincialis. In all cases, except one, we detected only the M genome. In the sperm of one male, we detected a paternal genome with an F-like primary sequence that was different from the sequence of the maternal genome in the animal's somatic tissues. We conclude that the male germ line is protected against invasion by the maternal genome. This is important because fidelity of gamete-specific transmission of the two mitochondrial genomes is a basic requirement for the stability of DUI.
贻贝科的物种拥有一种特殊的线粒体DNA（mtDNA）遗传系统，称为双亲单亲遗传（DUI），它由母系遗传的（F）和父系遗传的（M）线粒体基因组组成。雌性通常对于F基因组是同质性的，而雄性是异质性嵌合体，其体细胞组织由母系基因组主导，性腺由父系基因组主导。多项研究表明，母系基因组可能经常存在于雄性生殖系中。在此，我们报告了对超过30只地中海贻贝雄性个体的纯精子中线粒体DNA检查的结果。在所有情况中，除了一例，我们仅检测到M基因组。在一只雄性个体的精子中，我们检测到一个具有类似F的一级序列的父系基因组，该序列与该动物体细胞组织中的母系基因组序列不同。我们得出结论，雄性生殖系受到保护，免受母系基因组的侵入。这很重要，因为两个线粒体基因组的配子特异性遗传保真度是DUI稳定性的基本要求。
