Stern D B, Newton K J
Carnegie Institution of Washington, Department of Plant Biology, Stanford, California 94305.
Curr Genet. 1985;9(5):395-404. doi: 10.1007/BF00421611.
We have examined mitochondrial DNA (mtDNA) sequence conservation, transcriptional patterns of mitochondrial genes, and mitochondrial translation products in four species of the plant family Cucurbitaceae, in which there is a seven-fold range in mitochondrial genome size. A set of conserved mtDNA sequences which we term "core" DNA is present in all cucurbit genomes examined. In watermelon, only those mtDNA restriction fragments which contain "core" DNA hybridize with mtRNA. Similar numbers of polypeptides are synthesized by isolated mitochondria from all species examined, but an extra set of mtDNA sequences is transcribed in the largest genome (muskmelon). Taken together, these results suggest that some mtRNA is untranslated in muskmelon. Cloned mitochondrial genes of known function, from maize, identified mitochondrial transcripts that varied in both size and number among cucurbit species.
我们研究了葫芦科四个物种中线粒体DNA（mtDNA）序列的保守性、线粒体基因的转录模式以及线粒体翻译产物，这四个物种的线粒体基因组大小相差7倍。在所有检测的葫芦科基因组中都存在一组我们称为“核心”DNA的保守mtDNA序列。在西瓜中，只有那些包含“核心”DNA的mtDNA限制性片段能与mtRNA杂交。从所有检测物种中分离出的线粒体合成的多肽数量相似，但在最大基因组（甜瓜）中，有一组额外的mtDNA序列被转录。综合这些结果表明，在甜瓜中一些mtRNA未被翻译。从玉米中克隆出已知功能的线粒体基因，鉴定出葫芦科物种中线粒体转录本在大小和数量上均有所不同。
