Thermal adaptation in the wood tiger moth

Supervisor: Prof Chris Jiggins

This project will study variation in melanism in a moth and test the hypothesis that it represents an adaptation to climate.

As the global climate changes rapidly, understanding the evolutionary responses of populations becomes increasingly important. Here the student will study natural variation in black patterning in a moth in order to understand how populations are changing with the warming climate. Melanism is an important adaptation in insects to deal with altitudinal and latitudinal variation in temperature, so is expected to respond to climate warming. The wood tiger moth has a higher degree of melanism in its patterns in northern parts of the range, with southern populations polymorphic and with lower overall levels of melanism. We have good genomic resources for the species, with a reference genome, CRISPR methods optimised, as well as extensive field data from our collaborators in Finland including historic collections. The moths can be reared in the laboratory and are amenable to physiological and genetic experiments. In summary, this is an exciting system to study evolutionary responses to climate change and thermal adaptation in a well studied insect system.

The wood tiger moth has been well studied with respect to a colour polymorphism in the male hindwing. However there is also considerable standing genetic variation in the extent of black colouration. There are long term samples available and anecdotal evidence for reducing melanic forms as climate has warmed in the southerly range around Estonia and southern Finland. The project will therefore analyse historical samples to test for temporal trends. In addition, we will determine the genetic basis for melanic patterns using GWAS with whole genome sequencing, and test directly for allele frequency changes through time. Finally the project will also investigate functional effects using activity tests of moths with more or less melanism. Overall the project is an exciting opportunity to link genomic patterns with phenotype and function.

References

Yen, Eugenie C., et al. "A haplotype-resolved, de novo genome assembly for the wood tiger moth (Arctia plantaginis) through trio binning." GigaScience 9.8 (2020): giaa088.

Galarza, Juan A., et al. "Evaluating responses to temperature during pre-metamorphosis and carry-over effects at post-metamorphosis in the wood tiger moth (Arctia plantaginis)." Philosophical Transactions of the Royal Society B 374.1783 (2019): 20190295.

Brien, Melanie N., et al. "Colour polymorphism associated with a gene duplication in male wood tiger moths." bioRxiv (2022).