Birky C W
Department of Ecology and Evolutionary Biology, and Graduate Interdisciplinary Program in Genetics, The University of Arizona, Tucson 85721, USA.
Annu Rev Genet. 2001;35:125-48. doi: 10.1146/annurev.genet.35.102401.090231.
The inheritance of mitochondrial and chloroplast genes differs from that of nuclear genes in showing vegetative segregation, uniparental inheritance, intracellular selection, and reduced recombination. Vegetative segregation and some cases of uniparental inheritance are due to stochastic replication and partitioning of organelle genomes. The rate and pattern of vegetative segregation depend partly on the numbers of genomes and of organelles per cell, but more importantly on the extent to which genomes are shared between organelles, their distribution in the cell, the variance in number of replications per molecule, and the variance in numerical and genotypic partitioning of organelles and genomes. Most of these parameters are unknown for most organisms, but a simple binomial probability model using the effective number of genomes is a useful substitute. Studies using new cytological, molecular, and genetic methods are shedding some light on the processes involved in segregation, and also on the mechanisms of intracellular selection and uniparental inheritance in mammals. But significant issues remain unresolved, notably about the extent of paternal transmission and mitochondrial fusion in mammals.
线粒体和叶绿体基因的遗传与核基因不同，表现为营养分离、单亲遗传、细胞内选择和重组减少。营养分离和某些单亲遗传情况是由于细胞器基因组的随机复制和分配。营养分离的速率和模式部分取决于每个细胞中基因组和细胞器的数量，但更重要的是取决于基因组在细胞器之间共享的程度、它们在细胞中的分布、每个分子复制次数的方差，以及细胞器和基因组在数量和基因型分配上的方差。对于大多数生物来说，这些参数大多未知，但使用有效基因组数的简单二项式概率模型是一个有用的替代方法。使用新的细胞学、分子学和遗传学方法进行的研究正在揭示分离过程中涉及的一些过程，以及哺乳动物细胞内选择和单亲遗传的机制。但重大问题仍未解决，特别是关于哺乳动物中父系传递和线粒体融合的程度。
