果蝇中线粒体DNA的母系不完全遗传
Incomplete maternal transmission of mitochondrial DNA in Drosophila.
作者信息
Kondo R, Satta Y, Matsuura E T, Ishiwa H, Takahata N, Chigusa S I
机构信息
Department of Biology, Ochanomizu University, Tokyo, Japan.
出版信息
Genetics. 1990 Nov;126(3):657-63. doi: 10.1093/genetics/126.3.657.
The possibility of incomplete maternal transmission of mitochondrial DNA (mtDNA) in Drosophila, previously suggested by the presence of heteroplasmy, was examined by intra- and interspecific backcrosses of Drosophila simulans and its closest relative, Drosophila mauritiana. mtDNAs of offspring in these crosses were characterized by Southern hybridization with two alpha-32P-labeled probes that are specific to paternal mtDNAs. This method could detect as little as 0.03% paternal mtDNA, if present, in a sample. Among 331 lines that had been backcrossed for ten generations, four lines from the interspecific cross D. simulans (female) x D. mauritiana (male) showed clear evidence for paternal leakage of mtDNA. In three of these the maternal type was completely replaced while the fourth was heteroplasmic. Since in this experiment the total number of fertilization is known to be 331 x 10 = 3310, the proportion of paternal mtDNA per fertilization was estimated as about 0.1%. The mechanisms and evolutionary significance for paternal leakage are discussed in light of this finding.
先前因异质性的存在而被提出的果蝇中线粒体DNA（mtDNA）母系不完全遗传的可能性，通过拟暗果蝇及其近亲毛里求斯果蝇的种内和种间回交进行了研究。这些杂交后代的mtDNA通过与两种对父本mtDNA特异的α-32P标记探针进行Southern杂交来表征。如果样本中存在父本mtDNA，该方法能够检测低至0.03%的含量。在回交了十代的331个品系中，种间杂交拟暗果蝇（雌性）×毛里求斯果蝇（雄性）的四个品系显示出明显的父本mtDNA渗漏证据。其中三个品系中母本类型被完全取代，而第四个品系是异质的。由于在该实验中已知受精总数为331×10 = 3310，每次受精中父本mtDNA的比例估计约为0.1%。据此发现对父本渗漏的机制和进化意义进行了讨论。
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