Evolution of flower color pattern through selection on regulatory small RNAs

Corresponding author: Enrico Coen

Small RNAs (sRNAs) regulate genes in plants and animals. Here, we show that population-wide differences in color patterns in snapdragon (金鱼草) flowers are caused by an inverted duplication that generates sRNAs. The complexity and size of the transcripts indicate that the duplication represents an intermediate on the pathway to microRNA evolution. The sRNAs repress a pigment (色素) biosynthesis gene, creating a yellow highlight at the site of pollinator entry. The inverted duplication exhibits steep (急剧升降的) clines (渐变群) in allele frequency in a natural hybrid zone, showing that the allele is under selection. Thus, regulatory interactions of evolutionarily recent sRNAs can be acted upon by selection and contribute to the evolution of phenotypic diversity.

小RNA（sRNA）在动植物中调控基因的表达。本文显示在金鱼草群体之间花色的差异是由一段能够产生sRNA的插入重复引起的。转录本的复杂性和大小揭示了这段重复作为microRNA进化通路上的中间环节。sRNA抑制了一个色素生物合成的基因，从而导致金鱼草花部位的黄色高亮。在自然的杂合带这段插入重复的等位基因频率存在急剧变化的群体，表明该等位基因受到了选择。因此，选择对于近期演化出的sRNA调控互作起作用，进而导致了表型多样性的进化。

研究方向： 利用模式植物金鱼草、狸藻及拟南芥研究花和叶的生长。实验室主页：http://rico-coen.jic.ac.uk/index.php/Main_Page

doi: 10.1126/science.aao3526