Evolutionary active transposable elements in the genome of the coelacanth
Evolutionary active transposable elements in the genome of the coelacanth
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DOI：
10.1002/jez.b.22521
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发表时间：
2014-09-01
影响因子：
2.2
通讯作者：
Volff, Jean-Nicolas
中科院分区：
文献类型：
--
作者：
Chalopin, Domitille;Fan, Shaohua;Volff, Jean-Nicolas
腔棘鱼被许多人称为活化石，其谱系中明显的形态停滞被认为与其基因组的缓慢进化有因果关系，其转座因子（te）的活性强烈降低。对非洲腔棘鱼的分析表明，其基因组至少有25%由转座子组成，包括反转录转座子、内源性逆转录病毒和DNA转座子，其中非长末端重复（non-Long Terminal Repeat, non-LTR）反转录转座子具有很强的优势。腔棘鱼基因组在进化过程中经历了四次主要的转座爆发，其中LINE1、LINE2、CR1和Deu非ltr反转录转座子的主要贡献。许多转座因子在不同的组织中表达，可能具有活性。腔棘鱼和肺鱼中TE科的数量低于硬骨鱼，但高于鸡和人。这一观察结果与假说一致，即在进化过程中，许多TE家族在肉龙谱系中顺序消除。综上所述，我们的分析表明，腔棘鱼比鸟类和哺乳动物含有更多的TE家族，这些元素在腔棘鱼谱系的进化过程中一直很活跃。因此，在转座因子活性水平上，腔棘鱼基因组的进化似乎并不特别缓慢。J. Exp. Zool。（Mol. Dev. evolution .）中国科学院学报（自然科学版），2014。(c) 2013 Wiley Periodicals, Inc.；
The apparent morphological stasis in the lineage of the coelacanth, which has been called a living fossil by many, has been suggested to be causally related to a slow evolution of its genome, with strongly reduced activity of transposable elements (TEs). Analysis of the African coelacanth showed that at least 25% of its genome is constituted of transposable elements including retrotransposons, endogenous retroviruses and DNA transposons, with a strong predominance of non-Long Terminal Repeat (non-LTR) retrotransposons. The coelacanth genome has been shaped by four major general bursts of transposition during evolution, with major contributions of LINE1, LINE2, CR1, and Deu non-LTR retrotransposons. Many transposable elements are expressed in different tissues and might be active. The number of TE families in coelacanth, but also in lungfish, is lower than in teleost fish, but is higher than in chicken and human. This observation is in agreement with the hypothesis of a sequential elimination of many TE families in the sarcopterygian lineage during evolution. Taken together, our analysis indicates that the coelacanth contains more TE families than birds and mammals, and that these elements have been active during the evolution of the coelacanth lineage. Hence, at the level of transposable element activity, the coelacanth genome does not appear to evolve particularly slowly. J. Exp. Zool. (Mol. Dev. Evol.) 322B: 322-333, 2014. (c) 2013 Wiley Periodicals, Inc.