Koonin E V, Mushegian A R
National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, Maryland 20894, USA.
Curr Opin Genet Dev. 1996 Dec;6(6):757-62. doi: 10.1016/s0959-437x(96)80032-3.
The availability of complete genome sequences of cellular life forms creates the opportunity to explore the functional content of the genomes and evolutionary relationships between them at a new qualitative level. With the advent of these sequences, the construction of a minimal gene set sufficient for sustaining cellular life and reconstruction of the genome of the last common ancestor of bacteria, eukaryotes, and archaea become realistic, albeit challenging, research projects. A version of the minimal gene set for modern-type cellular life derived by comparative analysis of two bacterial genomes, those of Haemophilus influenzae and Mycoplasma genitalium, consists of approximately 250 genes. A comparison of the protein sequences encoded in these genes with those of the proteins encoded in the complete yeast genome suggests that the last common ancestor of all extant life might have had an RNA genome.
细胞生命形式完整基因组序列的可得性，为在新的定性水平上探索基因组的功能内容以及它们之间的进化关系创造了机会。随着这些序列的出现，构建足以维持细胞生命的最小基因集以及重建细菌、真核生物和古细菌的最后共同祖先的基因组，成为了现实但颇具挑战性的研究项目。通过对流感嗜血杆菌和生殖道支原体这两种细菌基因组的比较分析得出的现代型细胞生命的最小基因集版本，大约由250个基因组成。将这些基因中编码的蛋白质序列与完整酵母基因组中编码的蛋白质序列进行比较表明，所有现存生命的最后共同祖先可能拥有一个RNA基因组。
