This week, Sahr Wali joins to lab for a research practicum project. Sahr will be examining the effects of neuropeptide injections on thermal tolerance in Drosophila. Sahr was previously the lab fly food chef - a job she is graciously willing to continue while she tackles some important primary research. Welcome Sahr!
Gil Yerushalmi has officially joined the Donini lab. Gil will be working with Heath on an honours thesis about how salt stress can influence thermal tolerance in Drosophila melanogaster. Welcome Gil!
What a great week in Prague!
Myself, Lisa and James all presented posters at the annual main meeting of the Society for Experimental Biology in Prague. All three posters were very well received and I won the Irene Manton prize for the best poster in the animal section. James O'Sullivan and Lisa Jørgensen, both undergraduate students in the Overgaard lab, presented their outstanding work on ion balance disruption at high temperatures in insects and crustaceans, respectively.
Lisa Jørgensen stands with her awesome poster about the effects of heat stress on ion balance in the European green crab.
James O'Sullivan tries not to laugh beside his (very serious) poster about the effects of heat stress on locust ionoregulation.
A new article is now available in early view at the American Journal of Physiology, Regulatory, Integrative and Comparative Physiology. Here, we show that improvements in cold tolerance acquired through adult acclimation and acclimation during development are both associated with similar changes in ion and water balance.
This integrative study was a collaboration with Jonas Andersen, Volker Loeschcke and Johannes Overgaard, all at Aarhus University.
Read the abstract or download the paper here (sorry about the paywall!).
A new manuscript is now available (in early view) at JEB, entitled: Parallel ionoregulatory adjustments underlie phenotypic plasticity and evolution of Drosophila cold tolerance.
When exposed to low temperatures, many insects lose ion homeostasis, develop cold-induced injuries and die. Because low temperature performance is a key determinant of insect geographic distribution, understanding the mechanisms underlying this loss of ion balance is likely to be essential to developing predictive models of insect responses to climate change. Until now, however, it was unclear how ion homeostasis may be altered to improve cold tolerance, and how such alterations could be linked to extreme cold tolerance strategies.
In collaboration with colleagues at Western University and York University, I first demonstrate that species of the model insect genus Drosophila suffer a loss of ion balance at low temperatures, suggesting that the models developed for crickets and locusts apply to most insects. We then show that more cold-tolerant flies (both cold-acclimated individuals within a species, or more cold tolerant species) have altered hemolymph sodium balance and sodium pump activity.
Finally, we show that even if flies have reduced hemolymph cation concentrations, they maintain approximately similar hemolymph osmolality, presumably due to the accumulation of compatible osmolytes. This hypothesis is consistent with accumulations of small concentrations of carbohydrates and polyols in response to cold exposure in Drosophila, and allows us to hypothesize a mechanistic route for the (repeated) evolution of freeze tolerance and freeze avoidance.
The Overgaard lab just returned to Aarhus after an excellent trip to San Diego for the 2014 American Physiological Society Intersociety Meeting: Comparative Approaches to Grand Challenges in Physiology. Anders Findsen (second from the right) won a poster prize, and I was runner up in the Scholander competition for best oral presentation!
