Holland Peter W H
Department of Zoology, University of Oxford, OX1 3PS, UK.
Wiley Interdiscip Rev Dev Biol. 2013 Jan-Feb;2(1):31-45. doi: 10.1002/wdev.78. Epub 2012 Sep 10.
Many homeobox genes encode transcription factors with regulatory roles in animal and plant development. Homeobox genes are found in almost all eukaryotes, and have diversified into 11 gene classes and over 100 gene families in animal evolution, and 10 to 14 gene classes in plants. The largest group in animals is the ANTP class which includes the well-known Hox genes, plus other genes implicated in development including ParaHox (Cdx, Xlox, Gsx), Evx, Dlx, En, NK4, NK3, Msx, and Nanog. Genomic data suggest that the ANTP class diversified by extensive tandem duplication to generate a large array of genes, including an NK gene cluster and a hypothetical ProtoHox gene cluster that duplicated to generate Hox and ParaHox genes. Expression and functional data suggest that NK, Hox, and ParaHox gene clusters acquired distinct roles in patterning the mesoderm, nervous system, and gut. The PRD class is also diverse and includes Pax2/5/8, Pax3/7, Pax4/6, Gsc, Hesx, Otx, Otp, and Pitx genes. PRD genes are not generally arranged in ancient genomic clusters, although the Dux, Obox, and Rhox gene clusters arose in mammalian evolution as did several non-clustered PRD genes. Tandem duplication and genome duplication expanded the number of homeobox genes, possibly contributing to the evolution of developmental complexity, but homeobox gene loss must not be ignored. Evolutionary changes to homeobox gene expression have also been documented, including Hox gene expression patterns shifting in concert with segmental diversification in vertebrates and crustaceans, and deletion of a Pitx1 gene enhancer in pelvic-reduced sticklebacks. WIREs Dev Biol 2013, 2:31-45. doi: 10.1002/wdev.78 For further resources related to this article, please visit the WIREs website.
The author declares that he has no conflicts of interest.
许多同源异型基因编码在动植物发育中起调控作用的转录因子。同源异型基因几乎存在于所有真核生物中，在动物进化过程中已分化为11个基因类和100多个基因家族，在植物中为10至14个基因类。动物中最大的一类是ANTP类，其中包括著名的Hox基因，以及其他与发育相关的基因，如ParaHox（Cdx、Xlox、Gsx）、Evx、Dlx、En、NK4、NK3、Msx和Nanog。基因组数据表明，ANTP类通过广泛的串联重复而多样化，产生了大量基因，包括一个NK基因簇和一个假设的原始Hox基因簇，该基因簇复制后产生了Hox和ParaHox基因。表达和功能数据表明，NK、Hox和ParaHox基因簇在中胚层、神经系统和肠道的模式形成中获得了不同的作用。PRD类也多种多样，包括Pax2/5/8、Pax3/7、Pax4/6、Gsc、Hesx、Otx、Otp和Pitx基因。PRD基因一般不排列在古老的基因组簇中，尽管Dux、Obox和Rhox基因簇在哺乳动物进化过程中出现，还有几个非簇状PRD基因也是如此。串联重复和基因组重复增加了同源异型基因的数量，可能促进了发育复杂性的进化，但同源异型基因的丢失也不容忽视。同源异型基因表达的进化变化也有记录，包括脊椎动物和甲壳类动物中Hox基因表达模式与节段多样化协同变化，以及骨盆缩小的棘鱼中Pitx1基因增强子的缺失。《WIREs发育生物学》2013年，2:31 - 45。doi:10.1002/wdev.78 有关本文的更多资源，请访问WIREs网站。
作者声明他没有利益冲突。
