MacLean James A, Lorenzetti Diego, Hu Zhiying, Salerno Will J, Miller Jonathan, Wilkinson Miles F
Genesis. 2006 Mar;44(3):122-9. doi: 10.1002/gene.20193.
We recently reported the discovery of a homeobox gene cluster on the mouse X chromosome, Rhox, whose 12 members are selectively expressed in specific cell types in reproductive organs. Here we report the existence of 20 additional Rhox homeobox genes in this gene cluster. Most of the newly identified Rhox paralogs retain the same order and relative orientation as three of the originally described Rhox genes, suggesting that they arose from recent duplications of this trimer unit. Many of these new Rhox family members are expressed in the testis and placenta. Analysis of synonymous and nonsynonymous substitutions in their homeodomain region suggests that these new Rhox paralogs duplicated so recently that their encoded proteins have not yet acquired distinct DNA-binding specificities. The existence of these new Rhox genes provides an opportunity to examine the initial stages of gene cluster evolution.
我们最近报道了在小鼠X染色体上发现了一个同源框基因簇Rhox，其12个成员在生殖器官的特定细胞类型中选择性表达。在此，我们报道该基因簇中另外存在20个Rhox同源框基因。大多数新鉴定出的Rhox旁系同源基因与最初描述的三个Rhox基因保持相同的顺序和相对方向，这表明它们源于该三聚体单元最近的复制。这些新的Rhox家族成员中有许多在睾丸和胎盘中表达。对其同源结构域区域同义替换和非同义替换的分析表明，这些新的Rhox旁系同源基因复制时间很近，以至于它们编码的蛋白质尚未获得独特的DNA结合特异性。这些新Rhox基因的存在为研究基因簇进化的初始阶段提供了一个机会。
