Haemonchus contortus microtubules are cold resistant.

Molecular and biochemical parasitology

PubMedID: 24525483

Ashraf S, Prichard RK. Haemonchus contortus microtubules are cold resistant. Mol Biochem Parasitol. 2014;.
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 a- and ß-tubulin. In vitro polymerization of a- and ß-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°C. However, interestingly the microtubules of Haemonchus contortus are cold resistant i.e. they do not depolymerize at 0°C. Moreover these microtubules did not depolymerize even in the presence of 5mM CaCl2 or 50µM colchicine. These interesting findings may explain how larvae in the free living stages may survive cold temperatures over winter.