2023年2月10日出版的《科学》杂志发表了美国康涅狄格大学Yao-Wu Yuan等研究人员的最新合作成果。该研究发现，类群特异性的阶段性siRNA是猴面花中一个物种形成位点的基础。

研究人员报道了猴面花（Mimulthem）中的一个物种形成位点：YELLOW UPPER（YUP），其包含一个反向重复区域，该区域以分阶段模式产生小干扰RNA（siRNA）。尽管这种反向重复来源于一个与花色素沉着无关的蛋白质编码基因的部分重复，但其中一个siRNA靶向并抑制了花类胡萝卜素沉着的主要调控因子。YUP与两个蛋白质编码基因一起出现，这些基因作为Mimulthem亚分支中的“超位点”控制了花的其他方面，并促进了后代物种的表型多样化和传粉媒介介导的物种形成。

研究人员表示，类群特异性小RNA位点在真核生物基因组中广泛存在，但它们在谱系特异性适应、表型多样化和物种形成中的作用尚不清楚。

附：英文原文

Title: Taxon-specific, phased siRNAs underlie a speciation locus in monkeyflowers

Author: Mei Liang, Wenjie Chen, Amy M. LaFountain, Yuanlong Liu, Foen Peng, Rui Xia, H. D. Bradshaw, Yao-Wu Yuan

Issue&Volume: 2023-02-10

Abstract: Taxon-specific small RNA loci are widespread in eukaryotic genomes, yet their role in lineage-specific adaptation, phenotypic diversification, and speciation is poorly understood. Here, we report that a speciation locus in monkeyflowers (Mimulus), YELLOW UPPER (YUP), contains an inverted repeat region that produces small interfering RNAs (siRNAs) in a phased pattern. Although the inverted repeat is derived from a partial duplication of a protein-coding gene that is not involved in flower pigmentation, one of the siRNAs targets and represses a master regulator of floral carotenoid pigmentation. YUP emerged with two protein-coding genes that control other aspects of flower coloration as a “superlocus” in a subclade of Mimulus and has contributed to subsequent phenotypic diversification and pollinator-mediated speciation in the descendant species.

DOI: adf1323

Source: https://www.science.org/doi/10.1126/science.adf1323