USAP-DC

Antarctic channichthyid icefishes are stunning examples of the unique physiological traits that can arise during evolution in a constantly cold environment. Icefishes are the only vertebrates that as adults, lack the circulating oxygen-binding protein hemoglobin (Hb); several species within this family also lack the intracellular oxygen-binding protein myoglobin (Mb) in their heart ventricle. The loss of Hb and Mb has resulted in striking modifications in the cardiovascular system to ensure adequate tissue oxygenation, some of which are energetically costly. Recent indicate there may be at least one benefit to not expressing these heme-centered proteins - oxidized proteins and lipids are higher in red-blooded notothenioids compared to icefishes. The research will address the hypothesis that the loss of Hb and Mb reduces oxidative stress in icefishes compared to red-blooded notothenioid fishes, resulting in a lower rate of protein turnover and energetic cost savings. Specifically, the project will (1) Characterize levels of oxidative stress in red- and white-blooded notothenioid fishes, (2) Determine if red- and white-blooded notothenioids differ in their regulation of iron, (3) Determine if lower levels of oxidized proteins in icefishes result in lower rates of protein turnover and energetic cost savings, and (4) Determine if oxygen-binding proteins promote oxidative stress in-vivo and in-vitro.

The results will contribute to the understanding of iron-catalyzed oxidative stress, which is associated with the progression of Alzheimer's, Parkinson's and cardiovascular diseases. Moreover, the research will increase understanding of factors related to iron metabolism and oxidative stress in notothenioid fishes that may have played key roles in the success of channichthyid icefishes. The broader impacts include development of a website will enable teachers and students to learn more about the fascinating biology of Antarctic icefishes, as well as the impacts of global climate change and commercial fishing activities on Antarctic fishes. Additionally, Alaska Native high school and undergraduate students will be involved in research at the University of Alaska, Fairbanks.

Person	Role
Crockett, Elizabeth	Investigator
O'Brien, Kristin	Investigator

Antarctic Organisms and Ecosystems	Award # 1043781
Antarctic Organisms and Ecosystems	Award # 1043576

NSF-ANT10-43576
NSF-ANT10-43781_1

Deployment	Type
LMG1104	ship expedition

None in the Database

Repository	Title (link)	Format(s)	Status
USAP-DC	Electronic fishing logs	None	exist
USAP-DC	Redox Balance in Antarctic Notothenioid Fishes	None	exist
R2R	Expedition data of LMG1104	None	exists

1. O’Brien, K. M., Crockett, E. L., Philip, J., Oldham, C. A., Hoffman, M., Kuhn, D. E., … McLaughlin, J. (2017). The loss of hemoglobin and myoglobin does not minimize oxidative stress in Antarctic icefishes. The Journal of Experimental Biology, jeb.162503. (doi:10.1242/jeb.162503)
2. Kuhn, D. E., O’Brien, K. M., & Crockett, E. L. (2016). Expansion of capacities for iron transport and sequestration reflects plasma volumes and heart mass among white-blooded notothenioid fishes. American Journal of Physiology-Regulatory, Integrative and Comparative Physiology, 311(4), R649–R657. (doi:10.1152/ajpregu.00188.2016)
3. Lewis, J. M., Grove, T. J., & O’Brien, K. M. (2015). Energetic costs of protein synthesis do not differ between red- and white-blooded Antarctic notothenioid fishes. Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology, 187, 177–183. (doi:10.1016/j.cbpa.2015.05.026)
4. O’Brien, K. M., Mueller, I. A., Orczewska, J. I., Dullen, K. R., & Ortego, M. (2014). Hearts of some Antarctic fishes lack mitochondrial creatine kinase. Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology, 178, 30–36. (doi:10.1016/j.cbpa.2014.08.003)