Constitutive and variable patterns of genome-wide DNA methylation in populations from spatial-environmental range extremes of the bumble bee Bombus vosnesenskii

This project presents the first comprehensive analysis of CpG methylation in B. vosnesenskii, a widely distributed North American bumble bee species. We use very high-coverage whole-genome bisulfite sequencing WGBS) data from wild-caught specimens at the species' range extremes to (i) characterize the major trends in constitutive genome-wide methylation patterns and their potential functional roles, (ii) compare and contrast the epigenetic profiles from populations representing spatial and environmental range extremes (a warm southern low-elevation site and a cold northern high-elevation site) to assess intraspecific methylome variability and the putative roles of differentially methylated CpGs, and (iii) investigate the potential relationship between population genetic diversity and genome-wide CpG methylation. Overall, our findings highlight the factors that may shape CpG methylation patterns in bumble bees and provide foundational data for further investigations into epigenetic mechanisms involved in environmental adaptation and phenotypic plasticity in this ecologically and commercially important native pollinator species.

本项目首次针对北美广泛分布的沃氏熊蜂（B. vosnesenskii）开展CpG甲基化的系统性全面分析。本研究采用采自该物种种群分布极端区域的野生标本的超高覆盖度全基因组亚硫酸氢盐测序（whole-genome bisulfite sequencing, WGBS）数据，完成三项核心研究：其一，解析组成型全基因组甲基化模式的主要特征及其潜在功能作用；其二，对比代表空间与环境分布极端区域（温暖的南部低海拔采样点与寒冷的北部高海拔采样点）的种群表观遗传谱，以评估种内甲基化组变异及差异甲基化CpG位点的推定功能；其三，探究种群遗传多样性与全基因组CpG甲基化之间的潜在关联。综上，本研究结果揭示了可能塑造熊蜂CpG甲基化模式的关键因素，同时为进一步探究这种在生态与商业层面均具有重要价值的本土传粉昆虫的环境适应与表型可塑性相关表观遗传机制提供了基础数据。