USAP-DC

Antarctic notothenioid fishes exhibit two adaptive traits to survive in frigid temperatures. The first of these is the production of anti-freeze proteins in their blood and tissues. The second is a system-wide ability to perform cellular and physiological functions at extremely cold temperatures.The proposal goals are to show how Antarctic fishes use these characteristics to avoid freezing, and which additional genes are turned on, or suppressed in order for these fishes to maintain normal physiological function in extreme cold temperatures. Progressively colder habitats are encountered in the high latitude McMurdo Sound and Ross Shelf region, along with somewhat milder near?shore water environments in the Western Antarctic Peninsula (WAP). By quantifying the extent of ice crystals invading and lodging in the spleen, the percentage of McMurdo Sound fish during austral summer (Oct-Feb) will be compared to the WAP intertidal fish during austral winter (Jul-Sep) to demonstrate their capability and extent of freeze avoidance. Resistance to ice entry in surface epithelia (e.g. skin, gill and intestinal lining) is another expression of the adaptation of these fish to otherwise lethally freezing conditions.

The adaptive nature of a uniquely characteristic polar genome will be explored by the study of the transcriptome (the set of expressed RNA transcripts that constitutes the precursor to set of proteins expressed by an entire genome). Three notothenioid species (E.maclovinus, D. Mawsoni and C. aceratus) will be analysed to document evolutionary genetic changes (both gain and loss) shaped by life under extreme chronic cold. A differential gene expression (DGE) study will be carried out on these different species to evaluate evolutionary modification of tissue-wide response to heat challenges. The transcriptomes and other sequencing libraries will contribute to de novo ice-fish genome sequencing efforts.

Person	Role
Cheng, Chi-Hing	Investigator and contact
Devries, Arthur	Co-Investigator
Cziko, Paul	Researcher

Antarctic Organisms and Ecosystems	Award # 1142158
Antarctic Organisms and Ecosystems	Award # 0231006

USAP-0231006_1

None in the Database

Repository	Title (link)	Format(s)	Status
USAP-DC	High-resolution benthic seawater temperature record 1999-2012 (25-40m depth) from near intake jetty at McMurdo Station, Antarctica	ASCII	exists

1. Cziko et al., 2014 Antifreeze protein-induced superheating of ice inside Antarctic notothenioid fishes inhibits melting during summer warming PNAS. (doi:10.1073/pnas.1410256111)
2. Fields, L. G., & DeVries, A. L. (2015). Variation in blood serum antifreeze activity of Antarctic Trematomus fishes across habitat temperature and depth. Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology, 185, 43–50. (doi:10.1016/j.cbpa.2015.03.006)
3. Ceballos, S. G., Papetti, C., Babbucci, M., Fernández, D. A., Schiavon, L., & Cheng, C.-H. C. (2021). Genome-wide analysis reveals striking lack of genetic differentiation over long distances for the Antarctic toothfish Dissostichus mawsoni: High genetic connectivity or shared spawning grounds? Fisheries Research, 243, 106074. (doi:10.1016/j.fishres.2021.106074)
4. Bilyk, K. T., Vargas-Chacoff, L., & Cheng, C.-H. C. (2018). Evolution in chronic cold: varied loss of cellular response to heat in Antarctic notothenioid fish. BMC Evolutionary Biology, 18(1). (doi:10.1186/s12862-018-1254-6)
5. Bilyk, K. T., & DeVries, A. L. (2011). Heat tolerance and its plasticity in Antarctic fishes. Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology, 158(4), 382–390. (doi:10.1016/j.cbpa.2010.12.010)
6. Cuypers, B., Vermeylen, S., Hammerschmid, D., Trashin, S., Rahemi, V., Konijnenberg, A., … Van Doorslaer, S. (2017). Antarctic fish versus human cytoglobins – The same but yet so different. Journal of Inorganic Biochemistry, 173, 66–78. (doi:10.1016/j.jinorgbio.2017.04.025)
7. Murphy, K. R., Kalmanek, E. A., & Cheng, C.-H. C. (2016). Diversity and biogeography of larval and juvenile notothenioid fishes in McMurdo Sound, Antarctica. Polar Biology, 40(1), 161–176. (doi:10.1007/s00300-016-1939-5)