Project 21.3

Changing climates are driving declines of critical pollinators, including bees. To survive unfavourable conditions, many bees enter an obligate dormant state, characterised by reduced metabolism, arrested development, and increased stress tolerance. However, climate change may interfere with dormancy, causing phenological mismatches. This project will investigate gene expression and regulation in common pollinators to better understand evolutionary dynamics, focusing on both conserved and species-specific regulatory mechanisms during and after dormancy.

Environmental variation presents a major challenge for organisms, making effective responses to ensure survival and reproductive success essential. One evolutionary strategy to address this challenge is phenotypic plasticity, which is the ability of single genotypes to produce multiple phenotypes. This flexibility enables organisms to respond to heterogeneous environmental cues through functional, morphological, and physiological changes (Schneider 2022). Understanding whether such complex plastic traits influence ecological success is critical for assessing species’ resilience under different climatic scenarios.

One widespread form of phenotypic plasticity is dormancy. It allows organisms to escape unfavourable conditions and can be found across many taxa. Although dormancy varies among species, it can be generally characterized by reduced metabolic activity, arrest in development, and increased stress tolerance (Denlinger 2002).  With climatic alterations increasing in severity, ectothermic taxa such as insects are particularly vulnerable due to their dependence on ambient temperatures for homeostasis, highlighting the need to study how dormancy may be influenced by environmental shifts.

Different forms of dormancy have evolved in bees, making them an exemplar system to study dormancy (Santos et al. 2019). Dormant states can be found in both solitary and social bee species. For this project, we will concentrate on two representative genera: the solitary mason bee Osmia and the social bumblebee Bombus. Both groups can exhibit dormancy and are highly valued pollinators. While the physiological aspects of dormant states have been widely studied, the underlying gene expression and regulation driving this life-history strategy remain poorly understood.

Through transcriptomics, comparative population genomics, and evolutionary modelling, we will examine the expression and evolution of traits related to dormancy. Given the crucial role of gene regulation in adaptation, we will focus on the role of alternative splicing as a regulatory mechanism. Ultimately, we aim to deepen the understanding of the evolutionary dynamics of dormancy and provide insights into how organisms might respond to future environmental cues.