Chromosomal mapping of ANTP class homeobox genes in amphioxus: piecing together ancestral genomes
Chromosomal mapping of ANTP class homeobox genes in amphioxus: piecing together ancestral genomes
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DOI：
10.1046/j.1525-142x.2003.03052.x
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发表时间：
2003-09-01
影响因子：
2.9
通讯作者：
Hoiianda, PWH
中科院分区：
文献类型：
--
作者：
Castro, LFC;Hoiianda, PWH
同源异型盒基因编码DNA结合蛋白，其中许多涉及胚胎发育的控制。在进化上，大多数同源异型盒基因分为两个相关的分支：ANTP和PRD类。ANTP类中的一些基因，特别是Hox，ParaHox和NK基因，具有有趣的物理簇排列。为了研究这些基因簇的进化历史，我们研究了同源盒基因染色体定位在头索动物文昌鱼，文昌鱼。我们推断，22文昌鱼ANTP类同源盒基因定位在三条染色体。一个包含Hox集群加上AmphiEn，AmphiMnx和AmphiDll。ParaHox簇存在于另一条染色体中，而第三条染色体含有NK型同源框基因，包括AmphiMsx和ArnphiTlx。通过比较分析，我们推断，ANTP类同源异型盒基因的聚类进化只有一次，在一系列广泛的顺式复制事件的基因在动物进化的早期。后来发生了一个反式重复事件，在不同的染色体上产生Hox和ParaHox基因簇。所获得的结果有意义的同源异型盒基因聚类的起源，ANTP类同源异型盒基因的多样化，和动物基因组的进化。
Homeobox genes encode DNA-binding proteins, many of which are implicated in the control of embryonic development. Evolutionarily, most homeobox genes fall into two related clades: the ANTP and the PRD classes. Some genes in ANTP class, notably Hox, ParaHox, and NK genes, have an intriguing arrangement into physical clusters. To investigate the evolutionary history of these gene clusters, we examined homeobox gene chromosomal locations in the cephalochordate amphioxus, Branchiostoma floridae. We deduce that 22 amphioxus ANTP class homeobox genes localize in just three chromosomes. One contains the Hox cluster plus AmphiEn, AmphiMnx, and AmphiDll. The ParaHox cluster resides in another chromosome, whereas a third chromosome contains the NK type homeobox genes, including AmphiMsx and ArnphiTlx. By comparative analysis we infer that clustering of ANTP class homeobox genes evolved just once, during a series of extensive cis-duplication events of genes early in animal evolution. A trans-duplication event occurred later to yield the Hox and ParaHox gene clusters on different chromosomes. The results obtained have implications for understanding the origin of homeobox gene clustering, the diversification of the ANTP class of homeobox genes, and the evolution of animal genomes.