Coming out of the shell: building the molecular infrastructure for research on parasite-harbouring snails

[Extract] In Thailand and Laos alone, approximately 10 million people are infected with the liver fluke Opisthorchis viverrini [1]. Chronic infection with this parasite is considered the leading cause of cholangiocarcinoma (CCA, or bile-duct cancer) in large areas of Southeast Asia [2]. In these regions, CCA caused by O. viverrini is typically diagnosed 30–40 years after infection, with death occurring within 3–6 months post diagnosis [3]. O. viverrini is characterised by a three-host life cycle, with prosobranch snails of the genus Bithynia and cyprinid fishes acting as first and second intermediate hosts, respectively, while piscivorous mammals, including dogs, cats, and humans, act as definitive hosts [2]. Over the last two decades, much attention has been paid to studies on the epidemiology, developmental biology, and diagnosis of O. viverrini [4], while recent biotechnological advances are contributing large-scale explorations of the fundamental molecular biology of this liver fluke, with a view toward identifying key molecules essential for its development, reproduction, and survival, as well as dissecting the molecular pathways leading to the development of CCA [5]–[8]. These advances provide a solid foundation for the development of novel strategies to fight this devastating disease. However, long-term control of O. viverrini–induced cancer strictly relies on the development of integrated approaches, targeting the parasite as well as its intermediate hosts

Thermal effect on the life-cycle parameters of the medically important freshwater snail species lymnaea (radix) luteola (lamarck)

The snails Lymnaea (Radix) luteola exhibited marked variations in growth, longevity, and attaining sexual maturity at different temperatures and diets. At 10 C, irrespective of foods, pH and salinity of water, the snails had minimum life span, maximum death rate and lowest growth rate. At 15 C, the growth rate was comparatively higher and the snails survived for a few more days. But at these temperatures they failed to attain sexual maturity. Snails exposed to pH 5 and 9 at 20 , 25 , 30 , 35 C and room temperatures (19.6 -29.6 C); to 0.5, 1.5 and 2.5 NaCl at 20 and 35 C; to 2.5 NaCl at 25 C and room temperatures failed to attain sexual maturity. The snails exposed to pH 7 and different salinity grades at 20 , 25 , 30 , 35 C and room temperatures became sexually mature between 25-93 days depending upon the type of foods used in the culture