The evolution of the vertebrate Dlx gene family
The evolution of the vertebrate Dlx gene family
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DOI：
10.1073/pnas.93.20.10858
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发表时间：
1996-10-01
影响因子：
11.1
通讯作者：
Weiss, KM
中科院分区：
文献类型：
--
作者：
Stock, DW;Ellies, DL;Weiss, KM
脊椎动物Dlx基因家族由含有同源盒的转录因子组成，它们成对地分布在与Hox基因相同的染色体上。为了研究Dlx基因的进化史，我们克隆了5个新的斑马鱼家族成员，并提供了2个小鼠基因的额外序列信息。对Dlx基因序列的系统发育分析表明，在脊索动物和节肢动物分化之后，在被囊动物和脊椎动物分化之前，最初的串联重复产生了一对相连的Dlx基因。这对Dlx基因随后在染色体事件中被复制，导致了硬骨鱼和四足动物特征的四个Hox基因簇。哺乳动物可能丢失了一对与Hoxc基因簇相关的Dlx基因。我们无法区分骨脊椎动物的独立复制和祖先状态的保留，以解释斑马鱼中Dlx基因数量多于哺乳动物的存在。确定这些额外的斑马鱼Dlx基因与Hox簇的连锁关系将有助于解决这一问题。
The vertebrate Dlx gene family consists of homeobox-containing transcription factors distributed in pairs on the same chromosomes as the Hox genes. To investigate the evolutionary history of Dlx genes, we have cloned five new zebrafish family members and have provided additional sequence information for two mouse genes. Phylogenetic analyses of Dlx gene sequences considered in the context of their chromosomal arrangements suggest that an initial tandem duplication produced a linked pair of Dlx genes after the divergence of chordates and arthropods but prior to the divergence of tunicates and vertebrates. This pair of Dlx genes was then duplicated in the chromosomal events that led to the four clusters of Hox genes characteristic of bony fish and tetrapods. It is possible that a pair of Dlx genes linked to the Hoxc cluster has been lost from mammals. We were unable to distinguish between independent duplication and retention of the ancestral state of bony vertebrates to explain the presence of a greater number of Dlx genes in zebrafish than mammals. Determination of the linkage relationship of these additional zebrafish Dlx genes to Hox clusters should help resolve this issue.