Cold Tolerance and Physiological Mechanisms in Ticks

Abstract

Despite being poikilothermic organisms, ticks are known to inhabit northern regions with temperatures that annually drop below freezing during the winter months. Former research has been conducted on a variety of tick species to assess the limits of their cold tolerance and the mechanisms they use to live in such challenging temperature conditions. A proposed mechanism that aids the tick in cold tolerance is by synthesizing antifreeze proteins (AFPs) in the tick’s fluids; AFPs work by binding to formed ice crystals and preventing further growth.  Previously, an antifreeze glycoprotein was identified in Ixodes scapularis, and its presence increased cold tolerance in the tick species. This study aims to assess the survival limits of both Dermacentor variabilis and Dermacentor andersoni in challenging cold temperatures, and to monitor changes in AFP gene expression over time when ticks are exposed to cold temperature conditions.

Faculty Mentor: Kevin Friesen

Department: Biological Science (Honours)