Date of Graduation
5-2024
Document Type
Thesis
Degree Name
Bachelor of Science in Biology
Degree Level
Undergraduate
Department
Biological Sciences
Advisor/Mentor
Zhuang, Xuan
Committee Member/Reader
Beaulieu, Jeremy
Committee Member/Second Reader
Luu, Khoa
Abstract
Convergent evolution provides valuable insights into how natural selection shapes species traits. Genomic analysis of lineages that display convergent traits has the potential to identify candidate genes for environmental adaptations across the scope of entire genomes. One remarkable example of convergent evolution is the independent development of antifreeze proteins (AFPs) in phylogenetically distant polar fish lineages. While AFPs themselves are relatively well studied, the full genomic context of adaptation to freezing conditions in these fish lineages remains largely unexplored. Leveraging the whole genome sequences previously assembled in our lab, along with other high-quality genomes available in GenBank, I examined the genomes of freeze-resistant species and related non-resistant species across four teleost fish lineages: Pleuronectidae, Cottidae, Labridae, and Notothenioidei. Screening for orthogroup expansion and positive selection produced eight promising candidate genes identified in three or more of these lineages. Of these, RHO, Hsp70, and TP53BP1 have the clearest potential relation to the freezing and cold resistant traits that are characteristic of species that possess antifreeze proteins (AFP+ species). Further investigation of these genes could lead to insights into the mechanisms that facilitate tolerance to these extreme environments.
Keywords
Genomics, Adaptive Evolution, Convergent Evolution, Freeze Resistance
Citation
Talley, E. (2024). Exploring Genomic Convergence for Adaptations to Freezing Environments in Polar Fish. Biological Sciences Undergraduate Honors Theses Retrieved from https://scholarworks.uark.edu/biscuht/107
Included in
Computational Biology Commons, Genetics Commons, Genomics Commons