Andersson J O, Andersson S G
Department of Molecular Evolution, Uppsala University, Biomedical Center, Box 590, Uppsala, 751 24, Sweden.
Curr Opin Genet Dev. 1999 Dec;9(6):664-71. doi: 10.1016/s0959-437x(99)00024-6.
Studies of noncoding and pseudogene sequence diversity, particularly in Rickettsia, have begun to reveal the basic principles of genome degradation in microorganisms. Increasingly, studies of genes and genomes suggest that there has been an extensive amount of horizontal gene transfer among microorganisms. As this inflow of genetic material does not seem generally to have resulted in genome size expansions, however, degenerative processes must be at the very least as widespread as horizontal gene transfer. The basic principles of gene degradation and elimination that are being explored in Rickettsia are likely to be of major importance for our understanding of how microbial genomes evolve.
对非编码和假基因序列多样性的研究，尤其是对立克次氏体的研究，已开始揭示微生物基因组退化的基本原理。对基因和基因组的研究越来越多地表明，微生物之间存在大量的水平基因转移。然而，由于这种遗传物质的流入似乎一般并未导致基因组大小的增加，因此退化过程至少与水平基因转移一样普遍。在立克次氏体中正在探索的基因降解和消除的基本原理，可能对我们理解微生物基因组如何进化至关重要。
