Analysis of the exon-intron structures of fish, amphibian, bird and mammalian hatching enzyme genes, with special reference to the intron loss evolution of hatching enzyme genes in Teleostei
Analysis of the exon-intron structures of fish, amphibian, bird and mammalian hatching enzyme genes, with special reference to the intron loss evolution of hatching enzyme genes in Teleostei
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DOI：
10.1016/j.gene.2006.11.012
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发表时间：
2007-05-01
期刊：
影响因子：
3.5
通讯作者：
Iuchi, Ichiro
中科院分区：
文献类型：
--
作者：
Kawaguchi, Marl;Yasumasu, Shigeki;Iuchi, Ichiro
利用基因克隆和电子克隆技术，对脊椎动物孵化酶基因同源序列进行了结构分析。比较导致了一个假设，即日本鳗鱼的孵化酶基因保存的祖先结构的基因的鱼类，两栖动物，鸟类和哺乳动物。然而，真骨鱼类基因的外显子-内含子结构因种而异：日本鳗鲡孵化酶基因为9-外显子-8-内含子，斑马鱼为5-外显子-4-内含子。在本研究中，我们进一步分析的基因结构，鱼类属于。在真骨鱼类中，只有青鳉、红鳍东方鲀、黑绿河豚等棘鳍鱼类的孵化酶基因出现了HCE（high choryolytic enzyme）和LCE（low choryolytic enzyme）两种旁系同源基因的多样性。另外，HCE基因没有内含子，而LCE基因由8个外显子和7个内含子组成。系统发育分析表明，HCE和LCE基因是彼此的旁系同源，并在进化过程中分化到Escherichia pastoris。基因同线性和聚类分析结果表明，青鳉和Teraodon的HCE和LCE基因周围的同线性基因高度保守，而斑马鱼孵化酶基因周围没有发现这种同线性。我们推测斑马鱼孵化酶基因在进化过程中发生了染色体易位，并丢失了部分内含子。(c)2006 Elsevier B. V.保留所有权利。
Using gene cloning and in silico cloning, we analyzed the structures of hatching enzyme gene orthologs of vertebrates. Comparison led to a hypothesis that hatching enzyme genes of Japanese eel conserve an ancestral structure of the genes of fishes, amphibians, birds and mammals. However, the exon-intron structure of the genes was different from species to species in Teleostei: Japanese eel hatching enzyme genes were 9-exon-8-intron genes, and zebrafish genes were 5-exon-4-intron genes. In the present study, we further analyzed the gene structures of fishes belonging to Acanthopterygii. In the species of Teleostei we examined, diversification of hatching enzyme gene into two paralogous genes for HCE (high choriolytic enzyme) and LCE (low choriolytic enzyme) was found only in the acanthopterygian fishes such as medaka Oryzias latipes, Fundulus heteroclitus, Takifugu rubripes and Tetraodon nigroviridis. In addition, the HCE gene had no intron, while the LCE gene consisted of 8 exons and 7 introns. Phylogenetic analysis revealed that HCE and LCE genes were paralogous to each other, and diverged during the evolutionary lineage to Acanthopterygii. Analysis of gene synteny and cluster structure showed that the syntenic genes around the HCE and LCE genes were highly conserved between medaka and Teraodon, but such synteny was not found around the zebrafish hatching enzyme genes. We hypothesize that the zebrafish hatching enzyme genes were translocated from chromosome to chromosome, and lost some of their introns during evolution. (c) 2006 Elsevier B.V. All rights reserved.