Evolutionary dynamics of transposable elements during silkworm domestication
Evolutionary dynamics of transposable elements during silkworm domestication
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家蚕驯化过程中转座因子的进化动态
DOI：
10.1007/s13258-018-0713-1
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发表时间：
2018-10-01
期刊：
影响因子：
2.1
通讯作者：
Zhang, Hua-Hao
中科院分区：
文献类型：
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作者：
Han, Min-Jin;Xu, Hong-En;Zhang, Hua-Hao
虽然有一些关于模式生物中转座因子（TE）的种群动态的实例，但对驯化物种中TE的进化动态还没有系统的研究。本研究的目的是了解家蚕驯化过程中的TEs种群动态。在这项工作中，使用转座子显示，我们检查了7个TE家庭[他们代表了约59%的家蚕（家蚕）总TE含量]在4个家蚕种群和一个野桑蚕种群的多态性。最大似然法（ML）被用来估计选择压力。用AMOVA分析法和DIRECT CT程序分别进行群体分化和群体结构分析。转座子显示结果表明，家蚕与野桑蚕之间存在明显的差异。这些TEs在家蚕中经历了扩增和固定，而在野蚕中没有。此外，ML结果表明，家蚕的纯化选择作用明显弱于野蚕。有趣的是，发现了BmMITE-2诱导的适应性插入，该插入可降低其相邻的COQ 7基因侧翼区的多态性。这些结果表明，家蚕体内TEs的扩增和固定可能是由于家蚕驯化过程中的人口学效应和人工选择的结果。我们的结论是，本研究中提出的数据具有普遍意义的动物和作物的改进，以及在驯化新物种。
Although there are some documented examples on population dynamics of transposable elements (TEs) in model organisms, the evolutionary dynamics of TEs in domesticated species has not been systematically investigated. The objective of this study is to understand population dynamics of TEs during silkworm domestication. In this work, using transposon-display we examined the polymorphism of seven TE families [they represent about 59% of silkworm (Bombyx mori) total TE content] in four domesticated silkworm populations and one wild silkworm population. Maximum likelihood (ML) was used to estimate selection pressure. Population differentiation and structure were performed by using AMOVA analysis and program DISTRUCT, respectively. The results of transposon-display showed that significant differentiation occurred between the domesticated silkworm and wild silkworm. These TEs have experienced expansions and fixation in the domesticated silkworm but not in wild silkworm. Furthermore, the ML results indicated that purifying selection of TEs in the domesticated silkworm were significantly weaker than that in the wild silkworm. Interestingly, an adaptation insertion induced by BmMITE-2 was found, and this insertion can reduce the polymorphism of the flanking regions of its neighboringCOQ7gene. Our results suggested that TEs expanded and were fixed in the domesticated silkworm might result from demographic effects and artificial selection during domestication. We concluded that the data presented in this study have general implication in animal and crop improvements as well as in domestication of new species.