Differences in Acute Stress Response between Lab Adapted and Non-Lab Adapted Caenorhabditis remanei

Presenter: Catherine Ituarte, Biology

Organisms can adapt to the environments they inhabit in amazing ways, but sometimes adaptation to one environment can lead to a decrease in fitness in another environment. One example of this phenomenon is the potential difference in an organism’s ability to respond to stress depending on if the organism is kept in laboratory conditions or in its natural environment. I used the small nematode worm, Caenorhabditis remanei, to address the interplay between lab adaptation and stress response. I hypothesized
that populations that have adapted to laboratory conditions would be less stress resistant than non-lab adapted populations. Six populations of C.remanei were maintained under standard laboratory conditions for four months while six populations did not have prolonged exposure to laboratory conditions. These populations were then assayed for their resistance to acute heat and oxidative stress. The populations that were in the lab for four months had a lower average percent survival after an acute stress event than the populations that were not, supporting my hypothesis. These results suggest that evolving under laboratory conditions compromises an organism’s ability to respond to environmental stress, highlighting the importance of considering adaptation to laboratory conditions when designing experiments. My experiments form the basis for studying the complex relationship between an organism and its environment in this model organism, opening the possibility of identifying the genetic basis of this laboratory adaptation.