Mechanisms underlying metabolic suppression during insect diapause (PhD at Western University)
Most temperate insects spend over half their lives overwintering, where they face all sorts of nasty winter stressors such as low temperatures and food scarcity. To deal with these stressors, many insects enter a state of dormancy known as diapause. I’m interested in how insects modulate their metabolism during this period to save energy and live to tell the tale come spring.
Most diapausing insects suppress their metabolism anywhere from 5-90%, and I use the Colorado potato beetle as a model to understand how insects achieve these hypometabolic states. Read about some of my work on how diapause modulates metabolism-related gene expression here, and how Colorado potato beetles regulate their mitochondrial homeostasis to save energy during diapause here.
Adult Colorado potato beetles spend spring and summer living and feeding on fresh potato plants. 
Come autumn, beetles burrow into the soil and enter diapause where they lower their metabolism and wait until conditions improve in the spring. 
During diapause, Colorado potato beetles degrade most mitochondria in their flight muscle to save energy, and then regrow it on demand when they need to fly in the spring.
Function of the insect heat shock response at low temperatures (PhD at Western University)
When insects overwinter, they face extended periods below zero degrees Celsius. Because insects are ectotherms and cannot regulate their body temperature, long term exposure to these sub-zero temperatures can cause vital physiological processes to fail and important biological molecules to denature. I am interested in the strategies that insects use to mitigate these adverse effects of low temperatures so they can survive harsh and unpredictable winters.
In my PhD I examined how the Colorado potato beetle protects important proteins from being denatured in the cold, and the role that the cellular chaperone response plays in protein repair during the winter. Read about some of my work understanding how these beetles protect their cells in the cold in my PhD thesis here. This work is ongoing, and with a team of stellar undergrads and PhD students in the Sinclair Lab, we are now using genetic manipulation tools (RNA interference) to understand the function of 60 and 70 kDa sized heat shock proteins in protecting beetle cells in the cold.
Regulation of mitochondrial metabolism and muscle histolysis in wing polymorphic crickets (Postdoc at UC Berkeley)
In insects, flight capability frequently reduces reproductive investment, leading to wide-spread trade-offs between flight and reproduction. In many species of Gryllus field crickets, this trade-off results in the maintenance of a stable wing polymorphism, wherein some crickets emerge as long-winged adults with functional flight muscle and flight capability, and others emerge as short-winged adults whom are flight-incapable but reproduce earlier.
I’m interested in the metabolic basis for this trade-off, especially at the mitochondrial level. We already know that long-winged crickets have better fat body mitochondria (the insect tissue responsible for synthesizing and mobilizing fats to use for flight), and I’m on a quest to figure out how and why. Long-winged crickets eventually decide to invest in their reproduction, at which point they histolyze their flight muscle and lose flight capability altogether. I am also very interested in the mechanisms that regulate this histolysis, and how getting rid of flight muscle helps them re-invest their resources towards reproduction. This work is just getting started so stay tuned for publications!
Jackie Lebenzon, PhD 