USAP-DC

Polar regions are deserts that are not only cold but also lack access to free water. Antarctic insects have unique survival mechanisms including the ability to tolerate freezing and extensive dehydration, surviving the loss of 70% of their body water. How this is done is of interest not only for understanding seasonal adaptations of insects and how they respond to climate change, but the molecular and physiological mechanisms employed may offer valuable insights into more general mechanisms that might be exploited for cryopreservation and long-term storage of human tissues and organs for transplantation and other medical applications. The investigators will study the proteins that are responsible for removing water from the body, cell level consequences of this, and how the responsible genes vary between populations. The project will also further the NSF goals of making scientific discoveries available to the general public and of training new generations of scientists. Each year a K-12 teacher will be a member of the field team and assist with fieldwork and outreach to school children and their teachers. Educational outreach efforts include presentations at local schools and national teacher meetings, providing lesson plans and podcasts on a website, and continuing to publish articles related to this research in education journals. In addition, undergraduate and graduate students will receive extensive training in all aspects of the research project with extended experiences that include publication of scientific papers and presentations at national meetings.

This project focuses on deciphering the physiological and molecular mechanisms that enable the Antarctic midge Belgica antarctica to survive environmental stress and the loss of most of its body water in the desiccating polar environment. This extremophile is an ideal system for investigating mechanisms of stress tolerance and local geographic adaptations and its genome has recently been sequenced. This project has three focal areas: 1) Evaluating the role of aquaporins (water channel proteins) in the rapid removal of water from the body by studying expression of their genes during dehydration; 2) Investigating the mechanism of metabolic depression and the role of autophagy (controlled breakdown of cellular components) as a mediator of stress tolerance by studying expression of the genes responsible for autophagy during the dehydration process; and 3) Evaluating the population structure, gene flow, and adaptive variation in physiological traits associated with stress tolerance using a genetic approach that takes advantage of the genomic sequence available for this species coupled with physiological and environmental data from the sampled populations and their habitats.

Person	Role
Denlinger, David	Investigator and contact
Lee, Richard	Investigator

Antarctic Organisms and Ecosystems	Award # 1341393
Antarctic Organisms and Ecosystems	Award # 1341385

USAP-1341393_1

None in the Database

Repository	Title (link)	Format(s)	Status
NCBI GenBank	Alaskozetes antarcticus Raw sequence reads	None	exists
NCBI GenBank	Belgica antarctica Integrated Genome and Transcriptome Project	None	exists
Dryad	Data from: Rapid cold hardening protects against sublethal freezing injury in an Antarctic insect	None	exists

1. Spacht, D.E., N.M. Teets and D.L. Denlinger. 2018. Two isoforms of Pepck in Sarcophaga bullata and their distinct expression profiles through development, diapause, and in response to stresses of cold and starvation. Journal of Insect Physiology 111:41-46. (doi:10.1016/j.jinsphys.2018.10.008)
2. Meibers, H.E., G. Finch, R.T. Gregg, S. Glenn, K.D. Assani, E.C. Jennings, B. Davies, A.J. Rosendale, C.J. Holmes, J.D.Gantz, D.E. Spacht, R.E. Lee, Jr., D.L. Denlinger, M.T. Weirauch and J.B. Benoit. 2019. Sex- and developmental-specific transcriptomic analyses of the Antarctic mite, Alaskozetes antarcticus, reveal transcriptional shifts underlying oribatid mite reproduction. Polar Biology 42:357-370. (doi:10.1007/s00300-018-2427-x)
3. Kawarasaki, Y., N.M. Teets, B.N. Philip, L.J. Potts, J.D. Gantz, D.L. Denlinger and R.E. Lee, Jr. 2019. Characterization of drought-induced rapid cold-hardening in the Antarctic midge, Belgica antarctica. Polar Biology 42: 1147-1156. (doi:10.1007/s00300-019-02503-6)
4. Teets, N.M., Y. Kawarasaki, L.J. Potts, B.N. Philip, J.D. Ganz, D.L. Denlinger and R.E. Lee. Rapid cold hardening protects against sublethal freezing injury in an Antarctic insect. Journal of Experimental Biology 222, jeb206011. (doi:10.1242/jeb.206011)
5. Spacht, D. E., Gantz, J. D., Lee, R. E., & Denlinger, D. L. (2019). Onset of seasonal metabolic depression in the Antarctic midge Belgica antarctica appears to be independent of environmental cues. Physiological Entomology, 45(1), 16–21. (doi:10.1111/phen.12311)
6. Holmes, C. J., Jennings, E. C., Gantz, J. D., Spacht, D., Spangler, A. A., Denlinger, D. L., … Benoit, J. B. (2019). The Antarctic mite, Alaskozetes antarcticus, shares bacterial microbiome community membership but not abundance between adults and tritonymphs. Polar Biology, 42(11), 2075–2085. (doi:10.1007/s00300-019-02582-5)
7. Gantz, J. D., Spong, K. E., Seroogy, E., Robertson, R. M., & Lee, R. E. (2020). Effects of brief chilling and desiccation on ion homeostasis in the central nervous system of the migratory locust, Locusta migratoria. Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology, 110774. (doi:10.1016/j.cbpa.2020.110774)
8. Benoit, J. B., Oyen, K., Finch, G., Gantz, J. D., Wendeln, K., Arya, T., & Lee, R. E. (2021). Cold hardening improves larval tick questing under low temperatures at the expense of longevity. Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology, 257, 110966. (doi:10.1016/j.cbpa.2021.110966)
9. Ajayi, O. M., Gantz, J. D., Finch, G., Lee, R. E., Denlinger, D. L., & Benoit, J. B. (2021). Rapid stress hardening in the Antarctic midge improves male fertility by increasing courtship success and preventing decline of accessory gland proteins following cold exposure. Journal of Experimental Biology, 224(14). (doi:10.1242/jeb.242506)
10. Potts, L. J., Gantz, J. D., Kawarasaki, Y., Philip, B. N., Gonthier, D. J., Law, A. D., … Teets, N. M. (2020). Environmental factors influencing fine-scale distribution of Antarctica’s only endemic insect. Oecologia, 194(4), 529–539. (doi:10.1007/s00442-020-04714-9)
11. Davies, B., Rosendale, A. J., Gantz, J. D., Lee, R. E., Denlinger, D. L., & Benoit, J. B. (2021). Cross-tolerance and transcriptional shifts underlying abiotic stress in the seabird tick, Ixodes uriae. Polar Biology, 44(7), 1379–1389. (doi:10.1007/s00300-021-02887-4)
12. Teets, N. M., Dalrymple, E. G., Hillis, M. H., Gantz, J. D., Spacht, D. E., Lee, R. E., & Denlinger, D. L. (2019). Changes in Energy Reserves and Gene Expression Elicited by Freezing and Supercooling in the Antarctic Midge, Belgica antarctica. Insects, 11(1), 18. (doi:10.3390/insects11010018)
13. Spacht, D. E., Gantz, J. D., Devlin, J. J., McCabe, E. A., Lee, R. E., Denlinger, D. L., & Teets, N. M. (2021). Fine-scale variation in microhabitat conditions influences physiology and metabolism in an Antarctic insect. Oecologia. (doi:10.1007/s00442-021-05035-1)
14. Gantz, J. D., Spacht, D. E., & Lee, R. E. (2018). A preliminary survey of the terrestrial arthropods of the Rosenthal Islands, Antarctica. Polar Research, 37(1), 1500266. (doi:10.1080/17518369.2018.1500266)
15. Yi, S.-X., Gantz, J. D., & Lee, R. E. (2016). Desiccation enhances rapid cold-hardening in the flesh fly Sarcophaga bullata: evidence for cross tolerance between rapid physiological responses. Journal of Comparative Physiology B, 187(1), 79–86. (doi:10.1007/s00360-016-1030-0)