权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Molecular cytological studies on the mechanism of male mitochondria during maternal inheritance of mitochondria.

线粒体母系遗传过程中雄性线粒体机制的分子细胞学研究。

基本信息

批准号：
13440246
负责人：
KAWANO Shigeyuki
金额：
$ 8.7万
依托单位：
The University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2001
资助国家：
日本
起止时间：
2001 至 2002
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-13440246/
关键词：
maternal inheritance Physarum polycephalum Silene latifolia mitochondria mtDNA matA hierarchy selective digestion DNase

项目摘要

The fluorescence of mtDNA stained with DAPI in half of the mitochondria decreased simultaneously to give small spots, and then disappeared completely about 1 h after nuclear fusion, while the other mt-nucleoids and all of the mitochondrial sheaths remained unchanged in Physarum polycehalum. PCR analysis of single zygote cells confirmed that the loss was limited to mtDNA from one parent. The mt-nucleoid protein also dispersed soon after the digestion of mtDNA. The dispersed mt-nucleoid protein was eliminated from mitochondria. The vacant mitochondrial sheaths were gradually eliminated by 60 h after mating. Using six mating types, the transmission patterns of mtDNA were examined in all possible crosses. In 39 of 60 crosses, strict uniparental inheritance was confirmed in accordance with a hierarchy of relative sexuality. In the other crosses, however, mtDNA from both parents was transmitted to plasmodia. The ratio of parental mtDNA was estimated to be from 1:1 to 1:10^<-4>. Nevertheless, the matA hierarchy was followed. In these crosses, the mtDNA was incompletely digested, and mtDNA replicated during subsequent plasmodial development. We conclude that the rapid, selective digestion of mtDNA promotes the uniparental inheritance of mitochondria ; when this fails, biparental inheritance occurs. We used DNA zymography assays with native PAGE and SDS-PAGE to investigate the DNase activities in young zygotes, and identified two novel mitochondrial DNase activities a 50 kDa Ca^<2+>-dependent DNase, and a 13-kDa Mn^<2+>-+dependent DNase. We propose that the regulation of the mitochondrial nuclease by some unknown factor is the key to digestion of the mtDNA from one parent.

结果表明，在绒泡菌中，有一半线粒体的mtDNA荧光在DAPI染色后同时减弱，出现小斑点，在核融合后1 h左右完全消失，而其他线粒体类核和所有的线粒体鞘则保持不变。单个受精卵细胞的PCR分析证实，缺失仅限于来自一个亲本的mtDNA。线粒体类核蛋白也在消化后迅速分散。分散的线粒体类核蛋白从线粒体中被清除。交配后60 h，空线粒体鞘逐渐消失。利用6种交配类型，在所有可能的杂交中检测mtDNA的传递模式。在60个十字架，严格的单亲遗传证实按照相对性层次结构。然而，在其他杂交中，来自父母双方的mtDNA被传递给疟原虫。亲本mtDNA的比例估计为1：1 ~ 1：10<-4>。尽管如此，还是遵循了matA层次结构。在这些杂交中，mtDNA被不完全消化，并且mtDNA在随后的原质团发育期间复制。我们的结论是，线粒体DNA的快速，选择性消化促进单亲遗传的线粒体，当这失败，双亲遗传发生。我们用非变性PAGE和SDS-PAGE的DNA酶谱分析法研究了年轻合子中的DNA酶活性，并鉴定了两种新的线粒体DNA酶活性，一种是50 kDa的Ca^2+依赖性DNA酶，另一种是13 kDa的Mn^2+依赖性DNA酶。我们认为，线粒体核酸酶受某些未知因素的调节是消化来自一个亲本的mtDNA的关键。