Pinhal Danillo, Gonçalves Leandro de B, Campos Vinícius F, Patton James G
Genomics and Molecular Evolution Laboratory, Department of Chemical and Biological Sciences, Institute of Biosciences, DCQB, IBB, UNESP, Botucatu, SP, CEP 18618-689, Brazil.
Structural Genomics Laboratory, Graduate Program in Biotechnology, Technological Development Center, Federal University of Pelotas, Pelotas, RS, Brazil.
Cell Mol Life Sci. 2025 May 10;82(1):197. doi: 10.1007/s00018-025-05663-3.
miRNA arm switching is a pivotal regulatory mechanism that allows organisms to fine-tune gene expression by selectively utilizing either the 5p or 3p strand of a miRNA duplex. This process, conserved across species, facilitates adaptive responses to developmental cues, environmental changes, and disease states. By dynamically altering strand selection, arm switching reshapes gene regulatory networks, contributing to phenotypic diversity and evolutionary innovation. Despite its growing recognition, the mechanisms driving arm switching-such as thermodynamic properties and enzyme-mediated processing-remain incompletely understood. This review synthesizes current findings, highlighting arm switching as a highly conserved mechanism with profound implications for the evolution of regulatory networks. We explore how this phenomenon expands miRNA functionality, drives phenotypic plasticity, and co-evolves with miRNA gene duplications to fuel the diversification of biological functions across taxa.
微小RNA（miRNA）臂转换是一种关键的调控机制，它使生物体能够通过选择性地利用miRNA双链体的5p或3p链来微调基因表达。这一过程在物种间保守，有助于对发育线索、环境变化和疾病状态做出适应性反应。通过动态改变链的选择，臂转换重塑基因调控网络，促进表型多样性和进化创新。尽管其越来越受到认可，但驱动臂转换的机制，如热力学性质和酶介导的加工过程，仍未完全被理解。本综述综合了当前的研究结果，强调臂转换是一种高度保守的机制，对调控网络的进化具有深远影响。我们探讨了这种现象如何扩展miRNA的功能、驱动表型可塑性，并与miRNA基因复制共同进化，以推动生物功能在不同分类群中的多样化。
