My name is Yifei “Joye” Zhou, and I am a 4th year undergraduate student at the University of Wisconsin-Madison. Since joining the lab of Dr. Carol Eunmi Lee during my 2nd year of college, I have been deeply attracted to the genetics of non-model organisms and fascination of copepods.

At the International Conference on Copepoda 2024, I presented my preliminary results on the molecular evolution of the Alpha Carbonic Anhydrase (aCA) gene family across arthropods, with a focus on the Eurytemora affinis species complex. Recent studies from the Lee Lab have characterized the dramatic evolutionary response of the E. affinis species complex to rapid decline of salinity, which includes evolutionary changes in allele frequency and gene expression of its aCA paralogs. My study aims to understand whether aCA paralogs of the E. affinis species complex that is under positive selection during salinity change is also under elevated rates of evolution along its phylogenetic branch, in comparison to the average evolution rate of various arthropod aCA homologs. As a result, I presented a comprehensive phylogeny for the arthropod aCA gene family, including 294 distinct aCA sequences. Congruent with metazoan phylogeny, my arthropod aCA phylogeny showed basal divergence of sequences based on each protein’s predicted localization. Through selection analyses, I also found signatures of positive selection on the node branch leading to the aCA12 paralogs of E. affinis species complex, a gene that is implicated in salinity adaptation in these species from previous studies. However, other aCA paralogs of the E. affinis species complex that showed signatures of positive selection during salinity change did not show any signatures of selection when compared to arthropod aCA sequences.  This could suggest that these paralogs influence the salinity adaptation of E. affinis through regulatory evolution.

Being the first conference that I have attended, presenting at ICOC was a memorable, almost surreal experience that I will struggle to forget in the decades to come. The plethora of intriguing talks on parasitic copepods were truly motivating, and it allowed me to reconsolidate my fascination towards the biology of non-model organisms. This award that I have received will always motivate me to further my research in evolutionary genetics. I cannot thank more the WAC committee members, the University of Hiroshima, and my PI, Carol, for making this experience possible!