Department of Genetics and Evolutionary Biology, Universidade de São Paulo, Rua Do Matão, 277, São Paulo, SP, 05508-090, Brazil.
Department of Evolutionary Biology and Ecology, Interuniversity Institute of Bioinformatics in Brussels, Université Libre de Bruxelles, Avenue F.D. Roosevelt, 50, 1050, Brussels, Belgium.
Sci Rep. 2021 Feb 11;11(1):3654. doi: 10.1038/s41598-020-75432-8.
A striking feature of advanced insect societies is the existence of workers that forgo reproduction. Two broad types of workers exist in eusocial bees: nurses who care for their young siblings and the queen, and foragers who guard the nest and forage for food. Comparisons between these two worker subcastes have been performed in honeybees, but data from other bees are scarce. To understand whether similar molecular mechanisms are involved in nurse-forager differences across distinct species, we compared gene expression and DNA methylation profiles between nurses and foragers of the buff-tailed bumblebee Bombus terrestris and the stingless bee Tetragonisca angustula. These datasets were then compared to previous findings from honeybees. Our analyses revealed that although the expression pattern of genes is often species-specific, many of the biological processes and molecular pathways involved are common. Moreover, the correlation between gene expression and DNA methylation was dependent on the nucleotide context, and non-CG methylation appeared to be a relevant factor in the behavioral changes of the workers. In summary, task specialization in worker bees is characterized by a plastic and mosaic molecular pattern, with species-specific mechanisms acting upon broad common pathways across species.
高级昆虫社会的一个显著特征是存在放弃繁殖的工蜂。在群居蜜蜂中存在两种广泛的工蜂类型：照顾幼蜂和蜂王的保育员，以及守护巢穴和寻找食物的觅食者。在蜜蜂中已经对这两种工蜂亚群进行了比较，但其他蜜蜂的数据却很少。为了了解在不同物种之间的保育员-觅食者差异中是否涉及类似的分子机制，我们比较了熊蜂 Bombus terrestris 和无刺蜜蜂 Tetragonisca angustula 中保育员和觅食者之间的基因表达和 DNA 甲基化谱。然后，我们将这些数据集与之前从蜜蜂中获得的发现进行了比较。我们的分析表明，尽管基因表达模式通常是物种特异性的，但涉及的许多生物学过程和分子途径是共同的。此外，基因表达与 DNA 甲基化之间的相关性取决于核苷酸上下文，并且非 CG 甲基化似乎是工蜂行为变化的一个相关因素。总之，工蜂的任务专业化具有可塑性和镶嵌分子模式，具有特定于物种的机制，作用于跨越物种的广泛共同途径。
