Luke Graham N, Castro L Filipe C, McLay Kirsten, Bird Christine, Coulson Alan, Holland Peter W H
School of Animal and Microbial Sciences, University of Reading, Whiteknights, Reading RG6 6AJ, United Kingdom.
Proc Natl Acad Sci U S A. 2003 Apr 29;100(9):5292-5. doi: 10.1073/pnas.0836141100. Epub 2003 Apr 18.
The Drosophila melanogaster genome has six physically clustered NK-related homeobox genes in just 180 kb. Here we show that the NK homeobox gene cluster was an ancient feature of bilaterian animal genomes, but has been secondarily split in chordate ancestry. The NK homeobox gene clusters of amphioxus and vertebrates are each split and dispersed at two equivalent intergenic positions. From the ancestral NK gene cluster, only the Tlx-Lbx and NK3-NK4 linkages have been retained in chordates. This evolutionary pattern is in marked contrast to the Hox and ParaHox gene clusters, which are compact in amphioxus and vertebrates, but have been disrupted in Drosophila.
果蝇的基因组在仅180千碱基对的区域内有6个物理上成簇的与NK相关的同源异型盒基因。我们在此表明，NK同源异型盒基因簇是两侧对称动物基因组的一个古老特征，但在脊索动物的祖先中发生了二次分裂。文昌鱼和脊椎动物的NK同源异型盒基因簇分别在两个等效的基因间位置发生分裂和分散。从祖先的NK基因簇来看，在脊索动物中仅保留了Tlx-Lbx和NK3-NK4的连锁关系。这种进化模式与Hox和ParaHox基因簇形成了显著对比，后者在文昌鱼和脊椎动物中是紧凑的，但在果蝇中已被破坏。
