A comparative approach to the fecundity/longevity trade-off across two origins of eusociality in the bees

先进的社会性物种，如蜜蜂、切叶蚁或以真菌为食的白蚁，似乎已经扭转了繁殖力/长寿的生活史权衡，这是孤立的多细胞生物的基本原则；在这些群居物种中，蚁后的繁殖能力很高，但寿命比不育的工蜂长一到两个数量级。蜜蜂有超过20,000种，是研究与高级群居性相关的繁殖力/寿命权衡逆转的理想群体，因为它们在物种内部和物种之间都表现出广泛的社会行为。采用跨物种比较的方法，我们将通过转录组学分析独居、原始社会和高级社会蜜蜂物种的基因表达（通过转录组学），这些蜜蜂来自两个系统发育谱系，它们从独居的祖先独立进化出社会性：汗蜂（Halictinae）和圆巢蜂（Apinae）。我们将使用最新的生物信息学工具量化每个物种的年轻和年老雌性（包括工蜂和蜂王）之间的基因表达差异，以确定支撑繁殖力和寿命的基因。我们将对下一代测序数据进行补充，对被认为与生殖力或寿命有关的靶基因进行定量PCR分析，并对血淋巴中的关键内分泌标志物进行定量分析。兼性社会物种可能对这种方法特别有洞察力，并将纳入我们的物种选择。我们的总体目标是了解支持繁殖力和寿命的机械细节，以及它们如何以及在何处沿着社会性谱从孤独到群居。这些研究将很好地补充FOR2281研究单元内的其他项目，这些项目解决了蚂蚁和白蚁在昆虫社会复杂性的不同转变中繁殖力/寿命权衡的逆转。

Advanced eusocial species such as honey bees, leafcutter ants or fungus-growing termites seem to have reversed the fecundity/longevity life-history trade-off that is a basic tenet of solitary multicellular organisms; queens in these eusocial species have high reproductive output yet live for one or two orders of magnitude longer than their more-or-less sterile workers. Bees, comprising over 20,000 species, are an ideal group in which to investigate the reversal of the fecundity/longevity trade-off associated with advanced eusociality because they exhibit a wide range of social behaviours, both within and between species. Using a cross-species, comparative approach, we will analyse gene expression (via transcriptomics) of solitary, primitively eusocial and advanced eusocial bee species from two phylogenetic lineages of bee that have independently evolved eusociality from their solitary ancestors: the sweat bees (Halictinae) and the corbiculate bees (Apinae). We will quantify differences in gene expression between young and old females, including workers and queens, of each species using up-to-date bioinformatic tools so as to identify genes that underpin fecundity and longevity. We will complement these next generation sequencing data with quantitative PCR analyses of target genes thought to be involved in fecundity or longevity, and with quantification of key endocrine markers in haemolymph. Facultative social species may be particularly insightful for this approach, and will be incorporated into our selection of species. Our overall aim is to understand the mechanistic details underpinning fecundity and longevity, how and where they are reversed along the sociality spectrum from solitary to eusocial. These studies will complement well other projects within the Research Unit FOR2281 that address reversal of the fecundity/longevity trade-off in ants and termites across different transitions in insect social complexity.