Birky C W
Department of Molecular Genetics, Ohio State University, Columbus 43210, USA.
Proc Natl Acad Sci U S A. 1995 Dec 5;92(25):11331-8. doi: 10.1073/pnas.92.25.11331.
In nearly all eukaryotes, at least some individuals inherit mitochondrial and chloroplast genes from only one parent. There is no single mechanism of uniparental inheritance: organelle gene inheritance is blocked by a variety of mechanisms and at different stages of reproduction in different species. Frequent changes in the pattern of organelle gene inheritance during evolution suggest that it is subject to varying selective pressures. Organelle genes often fail to recombine even when inherited biparentally; consequently, their inheritance is asexual. Sexual reproduction is apparently less important for genes in organelles than for nuclear genes, probably because there are fewer of them. As a result organelle sex can be lost because of selection for special reproductive features such as oogamy or because uniparental inheritance reduces the spread of cytoplasmic parasites and selfish organelle DNA.
在几乎所有的真核生物中，至少有一些个体仅从一个亲本继承线粒体和叶绿体基因。单亲遗传不存在单一机制：细胞器基因的遗传在不同物种的不同繁殖阶段会被多种机制阻断。进化过程中细胞器基因遗传模式的频繁变化表明它受到不同的选择压力。即使是双亲遗传时，细胞器基因也常常无法重组；因此，它们的遗传是无性的。有性生殖对细胞器中的基因显然不如对核基因重要，可能是因为细胞器基因数量较少。结果，由于对特殊生殖特征（如卵式生殖）的选择，或者由于单亲遗传减少了细胞质寄生虫和自私细胞器DNA的传播，细胞器性可能会丧失。
