BACKGROUND The piwi-interacting RNAs (piRNAs) are small non-coding RNAs that specifically repress transposable elements (TEs) in the germline of Drosophila. Despite our expanding understanding of TE:piRNA interaction, whether there is an evolutionary arms race between TEs and piRNAs was unclear. RESULTS Here, we studied the population genomics of TEs and piRNAs in the worldwide strains of D. melanogaster. By conducting a correlation analysis between TE contents and the abundance of piRNAs from ovaries of representative strains of D. melanogaster, we find positive correlations between TEs and piRNAs in six TE families. Our simulations further highlight that TE activities and the strength of purifying selection against TEs are important factors shaping the interactions between TEs and piRNAs. Our studies also suggest that the de novo generation of piRNAs is an important mechanism to repress the newly invaded TEs. CONCLUSIONS Our results revealed the existence of an evolutionary arms race between the copy numbers of TEs and the abundance of antisense piRNAs at the population level. Although the interactions between TEs and piRNAs are complex and many factors should be considered to impact their interaction dynamics, our results suggest the emergence, repression specificity and strength of piRNAs on TEs should be considered in studying the landscapes of TE insertions in Drosophila. These results deepen our understanding of the interactions between piRNAs and TEs, and also provide novel insights into the nature of genomic conflicts of other forms.

中文翻译：

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果蝇中转座元件和 piRNA 之间的进化军备竞赛。


背景技术piwi相互作用RNA(piRNA)是小的非编码RNA，其特异性抑制果蝇种系中的转座元件(TE)。尽管我们对 TE:piRNA 相互作用的了解不断加深，但 TE 和 piRNA 之间是否存在进化军备竞赛尚不清楚。结果在这里，我们研究了全球黑腹果蝇品系中 TE 和 piRNA 的群体基因组学。通过对黑腹果蝇代表品系卵巢中 TE 含量与 piRNA 丰度进行相关分析，我们发现 6 个 TE 家族中 TE 与 piRNA 之间呈正相关。我们的模拟进一步强调，TE 活性和针对 TE 的纯化选择的强度是影响 TE 和 piRNA 之间相互作用的重要因素。我们的研究还表明，piRNA 的从头生成是抑制新入侵的 TE 的重要机制。结论 我们的结果揭示了群体水平上 TE 拷贝数和反义 piRNA 丰度之间存在进化军备竞赛。尽管 TE 和 piRNA 之间的相互作用很复杂，并且应考虑许多因素影响它们的相互作用动态，但我们的结果表明，在研究果蝇中 TE 插入的景观时，应考虑 piRNA 对 TE 的出现、抑制特异性和强度。这些结果加深了我们对 piRNA 和 TE 之间相互作用的理解，也为其他形式的基因组冲突的本质提供了新的见解。