Haemonchus contortus microtubules are cold resistant

Haemonchus contortus is an important nematode of livestock that is present in most parts of the world. The life cycle comprises free living stages (egg, L1, L2 and L3 larvae), and parasitic stages (L4, adult and egg) in a ruminant. Microtubules are filamentous structures which are made from polymerization of alpha-and beta-tubulin. In vitro polymerization of alpha- and beta-tubulin can be achieved by increasing the temperature to 37 C under certain conditions. As part of its normal functioning, in mammals, the microtubules can be depolymerized when the temperature is reduced to 0 degrees C. However, interestingly the microtubules of H. contortus are cold resistant i.e. they do not depolymerize at 0 degrees C. Moreover these microtubules did not depolymerize even in the presence of 5 mM CaCl2 or 50 mu M colchicine. These interesting findings may explain how larvae in the free living stages may survive cold temperatures over winter. (C) 2014 Elsevier B.V. All rights reserved.