Department of Microbiology and Plant Pathology, University of California, Riverside, CA, 92521, USA.
Department of Botany and Plant Sciences, University of California, Riverside, CA, 92521, USA.
Nat Commun. 2019 Feb 7;10(1):641. doi: 10.1038/s41467-019-08451-3.
Transposable elements (TEs) shape genome evolution through periodic bursts of amplification. In this study prior knowledge of the mPing/Ping/Pong TE family is exploited to track their copy numbers and distribution in genome sequences from 3,000 accessions of domesticated Oryza sativa (rice) and the wild progenitor Oryza rufipogon. We find that mPing bursts are restricted to recent domestication and is likely due to the accumulation of two TE components, Ping16A and Ping16A_Stow, that appear to be critical for mPing hyperactivity. Ping16A is a variant of the autonomous element with reduced activity as shown in a yeast transposition assay. Transposition of Ping16A into a Stowaway element generated Ping16A_Stow, the only Ping locus shared by all bursting accessions, and shown here to correlate with high mPing copies. Finally, we show that sustained activity of the mPing/Ping family in domesticated rice produced the components necessary for mPing bursts, not the loss of epigenetic regulation.
转座元件（TEs）通过周期性的扩增爆发来塑造基因组的进化。在这项研究中，利用 mPing/Ping/Pong TE 家族的先验知识来跟踪它们在 3000 个驯化的 Oryza sativa（水稻）和野生祖先 Oryza rufipogon 基因组序列中的拷贝数和分布。我们发现 mPing 爆发仅限于最近的驯化，这可能是由于两个 TE 成分 Ping16A 和 Ping16A_Stow 的积累，这两个成分似乎对 mPing 的过度活跃至关重要。Ping16A 是一个自主元素的变体，其活性降低，如酵母转座测定所示。Ping16A 转座到 Stowaway 元件中产生了 Ping16A_Stow，这是所有爆发品系共有的唯一 Ping 基因座，并且与高 mPing 拷贝数相关。最后，我们表明 mPing/Ping 家族在驯化水稻中的持续活性产生了 mPing 爆发所需的成分，而不是表观遗传调控的丧失。
