Kaneda H, Hayashi J, Takahama S, Taya C, Lindahl K F, Yonekawa H
Department of Laboratory Animal Science, Tokyo Metropolitan Institute of Medical Science, Japan.
Proc Natl Acad Sci U S A. 1995 May 9;92(10):4542-6. doi: 10.1073/pnas.92.10.4542.
To examine whether mtDNA is uni- or biparentally transmitted in mice, we developed an assay that can detect sperm mtDNA in a single mouse embryo. In intraspecific hybrids of Mus musculus, paternal mtDNA was detected only through the early pronucleus stage, and its disappearance co-incided with loss of membrane potential in sperm-derived mitochondria. By contrast, in interspecific hybrids between M. musculus and Mus spretus, paternal mtDNA was detected throughout development from pronucleus stage to neonates. We propose that oocyte cytoplasm has a species-specific mechanism that recognizes and eliminates sperm mitochondria and mtDNA. This mechanism must recognize nuclearly encoded proteins in the sperm midpiece, and not the mtDNA or the proteins it encodes, because sperm mitochondria from the congenic strain B6.mtspr, which carries M. spretus mtDNA on background of M. musculus (B6) nuclear genes, were eliminated early by B6 oocytes as in intraspecific crosses. We conclude that cytoplasmic genomes are transmitted uniparentally in intraspecific crosses in mammals as in Chlamydomonas and that leakage of parental mtDNA is limited to interspecific crosses, which rarely occur in nature.
为了研究小鼠中线粒体DNA（mtDNA）是单亲遗传还是双亲遗传，我们开发了一种能够在单个小鼠胚胎中检测精子mtDNA的检测方法。在小家鼠的种内杂交中，仅在原核早期检测到父本mtDNA，其消失与精子来源线粒体膜电位的丧失同时发生。相比之下，在小家鼠和西班牙小鼠的种间杂交中，从原核期到新生期的整个发育过程中都能检测到父本mtDNA。我们提出，卵母细胞细胞质具有一种物种特异性机制，可识别并消除精子线粒体和mtDNA。这种机制必须识别精子中段的核编码蛋白，而不是mtDNA或其编码的蛋白，因为携带小家鼠（B6）核基因背景下西班牙小鼠mtDNA的同基因系B6.mtspr的精子线粒体，如在种内杂交中一样，被B6卵母细胞早期消除。我们得出结论，与衣藻一样，哺乳动物种内杂交中细胞质基因组是单亲遗传的，并且亲本mtDNA的渗漏仅限于种间杂交，而种间杂交在自然界中很少发生。
