Eur. J. Entomol. 113: 537-541, 2016 | 10.14411/eje.2016.073

Cryoprotectant systems and cold tolerance of insects inhabiting central Yakutia (Russian Far East)

Natalia G. LI
Laboratory of Systematic and Ecology of Invertebrates, Institute for Biological Problems of Cryolithozone, Siberian Division of Russian Academy of Sciences, Lenin avenue 41, Yakutsk, 677980, Republic Sakha (Yakutia), Russian Federation; e-mail: li_natalia@mail.ru

Strong tolerance of freezing is an important strategy for insects living in extremely cold regions. They produce highly effective cryoprotectant systems consisting of ice-nucleating proteins and polyols, which enables tolerable freezing of the body fluid. Therefore, the measurement of the concentrations of polyols and the activity of ice nucleators in the haemolymph is an essential tool for describing tolerance to ice formation in insects occurring in particularly cold places. This study evaluates three parameters: insect body supercooling point (SCP), haemolymph glycerol content and the profile of haemolymph ice nucleating activity that characterize the strategies of cold adaptation and cold hardiness in two previously unstudied beetles, Chrysolina graminis graminis L. and Galerucella nymphaea L., inhabiting Yakutia (Russian Far East, latitude 62N). The high SCP values, ice nucleating activity and survival of the chrysomelids after freezing indicate that both species are tolerant of freezing. According to the profiles of ice-nucleating activity, the haemolymph from C. graminis graminis is characterized by a higher nucleating potential than that from G. nymphaea. The glycerol level is also higher in C. graminis graminis. The results indicate that both species develop tolerance to low temperatures, but the cold hardiness potential of C. graminis graminis is greater than that of G. nymphaea. This was revealed by the survival test, in which beetles were frozen to a temperature of -22C for 30 min; 86% of C. graminis graminis and 72% of G. nymphaea survived the test. Thus, the freeze-tolerance of these beetles seems to be based on the production of an integrated cryoprotectant system, the quality of which apparently influences the range of their cold resistance.

Keywords: Freeze-tolerance, ice nucleators, glycerol, cold hardiness potential, Siberian insects

Received: September 12, 2016; Accepted: October 7, 2016; Published online: November 2, 2016

Download citation

References

  1. Duman J.G., Wu D.W., Xu L., Tursman D. & Olsen M. 1991: Adaptations of insects to subzero temperature. - Quart. Rev. Biol. 66: 387-410. Go to original source...
  2. Gavrilova M.K. 1998: The Climates of Cold Regions of Earth. Siberian Division of Russian Academy of Sciences, Yakutsk, 234 pp.
  3. Kristiansen E., Li N.G., Averensky A.I. & Zachariassen K.E. 2009: The Siberian timberman Acanthocinus aedilis: a freeze-tolerant beetle with low supercooling points. - J. Comp. Physiol. (B) 179: 563-568. Go to original source...
  4. Lee R.E. 2010: A primer on insect cold-tolerance. In Delinger D.I. & Lee R.E. (eds): Insects at Low Temperatures. Cambridge University Press, UK, pp. 3-35.
  5. Li N.G. 2011: Ice nucleating activity of the Upis ceramboides hemolymph inhabiting central Yakutia. - Probl. Cryobiol. 21: 34-46.
  6. Li N.G. 2012: Relationships between cold hardiness, and ice nucleating activity, glycerol and protein contents in the hemolymph of caterpillars, Aporia crataegi L. - Cryoletters 33: 134-142.
  7. Li N.G. 2014: Physiological Mechanisms of Adaptation of Insects to the Dry and Cold Climate of Yakutia. PhD thesis, Kazan Federal University, Kazan, 203 pp.
  8. Li N.G. 2015: Water balance of freeze-tolerant insect larvae inhabiting arid areas in Eastern Siberia (Yakutia, Russia) - Euroas. Entomol. J. 14: 37-41.
  9. Li N.G. 2016: Strong tolerance to freezing is a major survival strategy in insects inhabiting central Yakutia (Sakha Republic, Russia), the coldest region in earth. - Cryobiology 73: 221-225. Go to original source...
  10. Miller K. 1985: Cold hardiness in invertebrate poikiloterms. - Comp. Biochem. Physiol. (A) 73: 595-605. Go to original source...
  11. Sinclair B.J., Addo-Bediako A. & Chown S.L. 2003: Climatic variability and the evolution of insect freeze tolerance. - Biol. Rev. 78: 181-195. Go to original source...
  12. Sinclair B.J., Alvarado L.E.C. & Ferguson L.V. 2015: An invitation to measure insect cold tolerance: Methods, approaches, and workflow. - J. Therm. Biol. 53: 180-197. Go to original source...
  13. Yeng K.L., Wolf E.E. & Duman J.G. 1991: A scanning tunneling microscopy study of an insect lipoprotein ice nucleator. - J. Vacuum Sci. Tech. 9: 1197-1201. Go to original source...
  14. Zachariassen K.E. 1985: Physiology of cold tolerance in insects. - Physiol. Rev. 65: 799-832.
  15. Zachariassen K.E. & Hammel H.T. 1988: The effect of ice-nucleating agents on ice-nucleating activity. - Cryobiology 25: 143-147. Go to original source...
  16. Zachariassen K.E. & Kristiansen E. 2003: What determines the strategy of cold-hardiness? - Acta Soc. Zool. Bohem. 67: 51-58.
  17. Zachariassen K.E., Baust J.G. & Lee R.J. 1982: A method for quantitative determination of ice nucleating agents in insect hemolymph. - Cryobiology 19: 180-184. Go to original source...
  18. Zachariassen K.E., Li N.G., Laugsand A.E., Kristiansen E. & Pedersen S.A. 2008: Is the strategy for cold hardiness in insects determined by their water balance? A study on two closely related families of beetles: Cerambycidae and Chrysomelidae. - J. Comp. Physiol. (B) 178: 977-984. Go to original source...