Molecular mechanisms of fission yeast adaptation to bee products – POMBEE

How does standing genetic variations emerge into phenotypic traits is a long-standing question in biology. For obvious practical reasons, our knowledge of the underlying mechanisms is largely derived from studies on a limited number of model organisms, propagated as inbred strains in controlled conditions. The idea behind our proposal is that including the ecological context and the range of genetic and phenotypic diversity present in wild relatives of model organisms is essential for advancnig the field. Here we propose to tackle this issue in the fission yeast clade, which natural history remains elusive. Fission yeasts diverged from budding yeasts more than 500 million years ago and comparative analyses brought both distinct and complementary information on fundamental processes.

We and others recently found that fission yeasts are enriched in bee food provisions, including honey, providing a long-sought reservoir of natural variation and the first hint towards their life history. We postulate that fission yeasts evolved phenotypic traits that shaped their interaction with bees and allowed adaptation to the high osmotic pressure characteristic of these substrates. Based on these findings, we developed an original interdisciplinary project combining expertise in yeast genetics and pollinator ecology, to explore the genetic basis of this adaptation and the ecological effects of fission yeasts within this niche. Specifically, our goals are to understand how fission yeasts modulate their haploid-diploid cycle in this environment, characterize their response to high osmolarity, explore how they establish themselves in bee products, and investigate their impact on bee development and fitness. Overall, we expect our project to provide a natural history context to fission yeast biology and, more generally, to provide a methodological framework for studying the genetic basis and ecological relevance of phenotypic traits in yeast.