Department of Biology, Case Western Reserve University, 44106, Cleveland, OH, USA.
Curr Genet. 1981 May;3(2):109-18. doi: 10.1007/BF00365714.
We have studied zygotic cytoplasmic mixing in two neutral petite by grande matings. Cytoplasmic mixing in zygotes and zygotic buds was followed histochemically and genetically. Both techniques showed that in most zygotes rapid cytoplasmic mixing occurred after early zygote formation and before first bud completion. The progeny mitochondrial genotypes produced from each cross were compatible with a model assuming random segregation of petite and grande inputs between the zygote and its first bud.While both crosses produced only grande zygotic colonies and grande diploid progeny when assayed by classical genetic methods, a class of events producing petite zygotes, retaining petite mitochondrial DNA, with grande first diploid buds was discovered. The results show that the expression of neutrality in our strains requires efficient cytoplasmic mixing during zygote maturation. The results suggest that the expression of mitochondrial genome neutrality requires competition or interaction between petite and grande parental mitochondrial DNA molecules. The possible nature of these phenomena is discussed.
我们研究了两个中性 petite 通过 grande 交配的合子细胞质混合。通过组织化学和遗传方法研究了合子和合子芽中的细胞质混合。这两种技术都表明，在大多数合子中，细胞质混合在早期合子形成后和第一个芽完成前迅速发生。从每个杂交中产生的后代线粒体基因型与一个假设模型是一致的，即 petite 和 grande 输入在合子与其第一个芽之间随机分离。虽然这两个杂交都只产生 grande 合子菌落和 grande 二倍体后代，当用经典遗传方法检测时，一类产生 petite 合子的事件被发现，这些合子保留了 petite 线粒体 DNA，并具有 grande 第一个二倍体芽。结果表明，我们的菌株中性表达需要在合子成熟过程中进行有效的细胞质混合。结果表明，线粒体基因组中性表达需要 petite 和 grande 亲本线粒体 DNA 分子之间的竞争或相互作用。讨论了这些现象的可能性质。
