Ruvinsky I, Silver L M, Gibson-Brown J J
Lewis Thomas Laboratory, Department of Molecular Biology, Princeton University, Princeton, New Jersey 08544, USA.
Genetics. 2000 Nov;156(3):1249-57. doi: 10.1093/genetics/156.3.1249.
The duplication of preexisting genes has played a major role in evolution. To understand the evolution of genetic complexity it is important to reconstruct the phylogenetic history of the genome. A widely held view suggests that the vertebrate genome evolved via two successive rounds of whole-genome duplication. To test this model we have isolated seven new T-box genes from the primitive chordate amphioxus. We find that each amphioxus gene generally corresponds to two or three vertebrate counterparts. A phylogenetic analysis of these genes supports the idea that a single whole-genome duplication took place early in vertebrate evolution, but cannot exclude the possibility that a second duplication later took place. The origin of additional paralogs evident in this and other gene families could be the result of subsequent, smaller-scale chromosomal duplications. Our findings highlight the importance of amphioxus as a key organism for understanding evolution of the vertebrate genome.
已有基因的复制在进化过程中发挥了重要作用。为了理解遗传复杂性的进化，重建基因组的系统发育史至关重要。一种广泛持有的观点认为，脊椎动物基因组是通过两轮连续的全基因组复制进化而来的。为了验证这一模型，我们从原始脊索动物文昌鱼中分离出了七个新的T-box基因。我们发现，文昌鱼的每个基因通常对应两个或三个脊椎动物的对应基因。对这些基因的系统发育分析支持了这样一种观点，即脊椎动物进化早期发生了一次全基因组复制，但不能排除后来发生第二次复制的可能性。在这个基因家族和其他基因家族中明显存在的额外旁系同源基因的起源，可能是随后发生的小规模染色体复制的结果。我们的研究结果突出了文昌鱼作为理解脊椎动物基因组进化的关键生物的重要性。
