Mitochondrial transmission during mating in Saccharomyces cerevisiae is determined by mitochondrial fusion and fission and the intramitochondrial segregation of mitochondrial DNA
Mitochondrial transmission during mating in Saccharomyces cerevisiae is determined by mitochondrial fusion and fission and the intramitochondrial segregation of mitochondrial DNA
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DOI：
10.1091/mbc.8.7.1233
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发表时间：
1997-07-01
影响因子：
3.3
通讯作者：
Walter, P
中科院分区：
文献类型：
--
作者：
Nunnari, J;Marshall, WF;Walter, P
为了深入了解酵母线粒体的传递过程，我们直接标记了线粒体蛋白和线粒体DNA (mtDNA)，并观察了它们在两个细胞融合后的命运。为此，用不同的荧光染料标记相反交配类型的单倍体细胞的线粒体蛋白，并在细胞交配后用荧光显微镜观察。亲本线粒体蛋白标记在整个受精卵中迅速重新分布和共定位，表明在交配过程中，亲本线粒体融合，它们的蛋白质含量混合，与之前用。单一亲本衍生的蛋白质标记。宽视场荧光显微镜对活细胞线粒体的三维结构和动力学分析表明，线粒体形成一个单一的动态网络，其连续性由裂变和融合事件的平衡频率维持。因此，线粒体蛋白的完全混合可以通过交配后形成一个连续的线粒体室来解释。与融合后亲本线粒体蛋白的混合形成鲜明对比的是，mtDNA（用胸腺嘧啶类似物5-溴脱氧尿嘧啶标记）仍然明显定位在受精卵细胞的一半。这一观察结果为遗传上观察到的mtDNA非随机传播模式提供了直接解释。我们认为，mtDNA在细胞器内的锚定与一种主动分离机制有关，该机制确保了mtDNA的准确遗传。细胞器。
To gain insight into the process of mitochondrial transmission in yeast, we directly labeled mitochondrial proteins and mitochondrial DNA (mtDNA) and observed their fate after the fusion of two cells. To this end, mitochondrial proteins in haploid cells of opposite mating type were labeled with different fluorescent dyes and observed by fluorescence microscopy after mating of the cells. Parental mitochondrial protein markers rapidly redistributed and colocalized throughout zygotes, indicating that during mating, parental mitochondria fuse and their protein contents intermix, consistent with results previously obtained with. a single parentally derived protein marker. Analysis of the three-dimensional structure and dynamics of mitochondria in living cells with wide-field fluorescence microscopy indicated that mitochondria form a single dynamic network, whose continuity is maintained by a balanced frequency of fission and fusion events. Thus, the complete mixing of mitochondrial proteins can be explained by the formation of one continuous mitochondrial compartment after mating. In marked contrast to the mixing of parental mitochondrial proteins after fusion, mtDNA (labeled with the thymidine analogue 5-bromodeoxyuridine) remained distinctly localized to one half of the zygotic cell. This observation provides a direct explanation for the genetically observed nonrandom patterns of mtDNA transmission. We propose that anchoring of mtDNA within the organelle is linked to an active segregation mechanism that ensures accurate inheritance of mtDNA along with. the organelle.