Asymmetrically reduced expression of hand1 homeologs involving a single nucleotide substitution in a cis-regulatory element.
Asymmetrically reduced expression of hand1 homeologs involving a single nucleotide substitution in a cis-regulatory element.
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DOI：
10.1016/j.ydbio.2017.03.021
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发表时间：
2017-05
影响因子：
2.7
通讯作者：
H. Ochi;Nanoka Suzuki;Akane Kawaguchi;H. Ogino
中科院分区：
文献类型：
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作者：
H. Ochi;Nanoka Suzuki;Akane Kawaguchi;H. Ogino
在脊椎动物进化过程中，全基因组复制导致大量重复基因，其中一些最终通过改变顺式调控序列而改变其表达模式和/或水平。然而，这种顺位监管改革所涉及的最初过程仍不清楚。因此，我们通过分析1700万-1800万年前异源四倍化产生的非洲爪哇(hand1.Landhand1.S)的重复hand1基因来研究这一过程，并将这些基因与它们在祖先型二倍体物种X中的单个直系同源基因进行比较。热带鱼。DN/DS分析表明，它们仍处于纯化选择中，因此，它们的产品似乎保留了祖先的功能特性。RNA-seq和原位杂交分析表明，1.Land1.Sare彼此具有相似的表达模式和毒素。热带L1在原始心脏中的表达水平远低于Hand1。比较序列分析、荧光素酶报告分析、芯片-PCR分析和转基因报告分析表明，Hand1启动子上的单核苷酸替换是导致心脏表达降低的原因。这些发现表明，在年轻的复制基因组中，启动子序列的微小变化可以在其编码蛋白功能多样化之前触发复制基因表达的多样化。
During vertebrate evolution, whole genome duplications resulted in a number of duplicated genes, some of which eventually changed their expression patterns and/or levelsviaalteration ofcis-regulatory sequences. However, the initial process involved in suchcis-regulatory changes remains unclear. Therefore, we investigated this process by analyzing the duplicatedhand1genes ofXenopus laevis(hand1.Landhand1.S), which were generated by allotetraploidization 17–18 million years ago, and compared these with their single ortholog in the ancestral-type diploid speciesX. tropicalis. A dN/dS analysis indicated thathand1.Landhand1.Sare still under purifying selection, and thus, their products appear to retain ancestral functional properties. RNA-seq andin situhybridization analyses revealed thathand1.Landhand1.Shave similar expression patterns to each other and toX. tropicalis hand1, but thehand1.Sexpression level was much lower than thehand1.Lexpression level in the primordial heart. A comparative sequence analysis, luciferase reporter analysis, ChIP-PCR analysis, and transgenic reporter analysis showed that a single nucleotide substitution in thehand1.Spromoter was responsible for the reduced expression in the heart. These findings demonstrated that a small change in the promoter sequence can trigger diversification of duplicated gene expression prior to diversification of their encoded protein functions in a young duplicated genome.