Submission Type
Oral Presentation
Abstract
The Dissostichus genus of notothenioid fish contains two giant, iconic sister species, Dissostichus mawsoni (Antarctic toothfish) and Dissostichus eleginoides (Patagonian toothfish), which inhabit thermally distinct environments. D. mawsoni is protected by antifreeze glycoproteins (AFGPs) from freezing in the cold waters of the Southern Ocean, while D. eleginoides lacks detectable antifreeze activity despite its recent divergence. Interestingly, recent evidence suggests the possibility of a third species in the Dissostichus genus, which is currently believed to be a separate population of D. eleginoides closer to the Southern Ocean whose genome has recently been published. Our study focuses on D. eleginoides specimens from further north to determine what changes occurred in the D. eleginoides genome that resulted in the loss of AFGP activity. One hypothesis is that an evolutionary event resulted in the deletion of the entire AFGP gene family in the D. eleginoides lineage. The other possibility is that D. eleginoides never developed an antifreeze trait and is also absent in the common ancestor of the two sister species. To test these hypotheses, we sequenced, assembled, and annotated the nuclear and mitochondrial genomes of both D. mawsoni and D. eleginoides and employed comparative genomics tools to compare structural variations in the respective genomes and to investigate the existence of a third Dissostichus species. By analyzing the genomes of D. mawsoni and D. eleginoides, we aim to shed light on the mechanisms underlying the adaptation of these fish in their respective environments and to aid in conservation efforts of these Antarctic species.
Included in
Bioinformatics Commons, Computational Biology Commons, Evolution Commons, Marine Biology Commons
Genomic basis of antifreeze trait divergence in Antarctic and Patagonian toothfish
The Dissostichus genus of notothenioid fish contains two giant, iconic sister species, Dissostichus mawsoni (Antarctic toothfish) and Dissostichus eleginoides (Patagonian toothfish), which inhabit thermally distinct environments. D. mawsoni is protected by antifreeze glycoproteins (AFGPs) from freezing in the cold waters of the Southern Ocean, while D. eleginoides lacks detectable antifreeze activity despite its recent divergence. Interestingly, recent evidence suggests the possibility of a third species in the Dissostichus genus, which is currently believed to be a separate population of D. eleginoides closer to the Southern Ocean whose genome has recently been published. Our study focuses on D. eleginoides specimens from further north to determine what changes occurred in the D. eleginoides genome that resulted in the loss of AFGP activity. One hypothesis is that an evolutionary event resulted in the deletion of the entire AFGP gene family in the D. eleginoides lineage. The other possibility is that D. eleginoides never developed an antifreeze trait and is also absent in the common ancestor of the two sister species. To test these hypotheses, we sequenced, assembled, and annotated the nuclear and mitochondrial genomes of both D. mawsoni and D. eleginoides and employed comparative genomics tools to compare structural variations in the respective genomes and to investigate the existence of a third Dissostichus species. By analyzing the genomes of D. mawsoni and D. eleginoides, we aim to shed light on the mechanisms underlying the adaptation of these fish in their respective environments and to aid in conservation efforts of these Antarctic species.
Comments
Dr. C.-H. Christina Cheng, University of Illinois at Urbana-Champaign