Balancing selection on an MYB transcription factor maintains the twig trichome color variation in Melastoma normale

BMC Biology

Research Article

Yongmei Chen¹  Kai Zeng²  Shulin Deng³  Zulin Ning³  Peishan Zou⁴  Qiang Fan⁴  Ying Liu⁴  Wei Wu⁴  Guilian Huang⁴  Xueke Zhi⁴  Renchao Zhou⁴ 

[1] College of Chemical Engineering, Sichuan University of Science & Engineering, 643000, Zigong, Sichuan, China;Department of Animal and Plant Sciences, University of Sheffield, Sheffield, UK;Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, 510650, Guangzhou, China;State Key Laboratory of Biocontrol and Guangdong Provincial Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-Sen University, 510275, Guangzhou, China;

关键词: Genetic basis;    Balancing selection;    Color variation;    Introgression;    Melastoma;   

DOI  :  10.1186/s12915-023-01611-4

 received in 2022-08-01, accepted in 2023-05-03,  发布年份 2023

来源: Springer

【 摘 要 】

BackgroundThe factors that maintain phenotypic and genetic variation within a population have received long-term attention in evolutionary biology. Here the genetic basis and evolution of the geographically widespread variation in twig trichome color (from red to white) in a shrub Melastoma normale was investigated using Pool-seq and evolutionary analyses.ResultsThe results show that the twig trichome coloration is under selection in different light environments and that a 6-kb region containing an R2R3 MYB transcription factor gene is the major region of divergence between the extreme red and white morphs. This gene has two highly divergent groups of alleles, one of which likely originated from introgression from another species in this genus and has risen to high frequency (> 0.6) within each of the three populations under investigation. In contrast, polymorphisms in other regions of the genome show no sign of differentiation between the two morphs, suggesting that genomic patterns of diversity have been shaped by homogenizing gene flow. Population genetics analysis reveals signals of balancing selection acting on this gene, and it is suggested that spatially varying selection is the most likely mechanism of balancing selection in this case.ConclusionsThis study demonstrate that polymorphisms on a single transcription factor gene largely confer the twig trichome color variation in M. normale, while also explaining how adaptive divergence can occur and be maintained in the face of gene flow.

【 授权许可】

CC BY   
© The Author(s) 2023

【 图 表 】

41116_2023_36_Article_IEq194.gif

41116_2023_36_Article_IEq188.gif

41116_2023_36_Article_IEq178.gif

41116_2023_36_Article_IEq175.gif

41116_2023_36_Article_IEq135.gif

41116_2023_36_Article_IEq133.gif