Lokal anpassning och genomevolution hos planktoniska kräftdjur: vad har storleken för betydelse?
Tidsperiod: 2019-01-01 till 2022-12-31
Projektledare: Andreas Wallberg
Budget: 3 700 000 SEK
Animals and plants show striking variation in genome size and structure, but it is unclear if it is the result of neutral processes or adaptation. What is the advantage of having a large genome? Over four years, I will lead a team studying adaptation and genome evolution in two groups of crustacean zooplankton: Calanus copepods and krill. They have large and rapidly evolving genomes that correlate in size with habitat and fitness-related traits. They are believed to be relatively unaffected by genetic drift, making them great models for uncovering adaptive aspects of genome evolution.First, we plan to use state-of-the-art technologies to assemble the genomes of two Calanus species and characterize rapidly evolving genomic regions. In these species, individuals have ~25% larger genomes at high latitudes. By mapping genetic and functional variation, we will assess whether the unique regions may be locally adaptive. Second, we will estimate genome sizes and phylogenetic interrelationships between 20 krill species using flow-cytometry and transcriptomes. We will trace genome evolution in this group and test how size-changes are associated with selection or neutral processes. Third, we will test if temperature stress activates transposable elements in copepods, and might help drive genomic change. Our project will uncover the mechanisms of adaptation in these important zooplankton and may help explain the value of the non-coding DNA that make up most of the genomes in eukaryotes.