Department of Biology, University of New Mexico, Albuquerque, NM 87131, USA.
Curr Biol. 2011 Feb 22;21(4):306-10. doi: 10.1016/j.cub.2011.01.026. Epub 2011 Feb 3.
Gene and genome duplications are the primary source of new genes and novel functions and have played a pivotal role in the evolution of genomic and organismal complexity. The spontaneous rate of gene duplication is a critical parameter for understanding the evolutionary dynamics of gene duplicates; yet few direct empirical estimates exist and differ widely. The presence of a large population of recently derived gene duplicates in sequenced genomes suggests a high rate of spontaneous origin, also evidenced by population genomic studies reporting rampant copy-number polymorphism at the intraspecific level. An analysis of long-term mutation accumulation lines of Caenorhabditis elegans for gene copy-number changes with array comparative genomic hybridization yields the first direct estimate of the genome-wide rate of gene duplication in a multicellular eukaryote. The gene duplication rate in C. elegans is quite high, on the order of 10(-7) duplications/gene/generation. This rate is two orders of magnitude greater than the spontaneous rate of point mutation per nucleotide site in this species and also greatly exceeds an earlier estimate derived from the frequency distribution of extant gene duplicates in the sequenced C. elegans genome.
基因和基因组重复是新基因和新功能的主要来源，在基因组和生物体复杂性的进化中发挥了关键作用。基因重复的自发率是理解基因重复进化动态的关键参数；然而，很少有直接的经验估计存在，而且差异很大。在已测序的基因组中存在大量最近衍生的基因重复，表明自发起源的速度很高，这也被报道在种内水平存在大量拷贝数多态性的群体基因组研究所证实。通过对秀丽隐杆线虫的长期突变积累系进行基因拷贝数变化的阵列比较基因组杂交分析，得出了多细胞真核生物中全基因组基因重复率的第一个直接估计。秀丽隐杆线虫的基因重复率相当高，大约为每基因每代 10(-7) 次重复。这个速率比该物种中每个核苷酸位点的点突变自发率高出两个数量级，也大大超过了从已测序的秀丽隐杆线虫基因组中现存基因重复的频率分布中得出的早期估计。
