Matsukura Keiichiro, Tsumuki Hisaaki, Izumi Yohei, Wada Takashi
Research Team for Insect and Nematode Management, National Agricultural Research Center for Kyushu Okinawa Region, Suya 2421, Koshi, Kumamoto 861-1192, Japan.
Cryobiology. 2008 Apr;56(2):131-7. doi: 10.1016/j.cryobiol.2007.12.001. Epub 2007 Dec 8.
The apple snail, Pomacea canaliculata, is an invasive freshwater snail. It increases its cold hardiness before winter. However, the physiological mechanism of cold hardiness in molluscs is poorly understood, especially in freshwater molluscs. In this study, we examined the changes in low molecular weight compounds, glycogen and lipids, in the body of P. canaliculata in association with the development of cold hardiness. When snails without cold hardiness were experimentally cold-acclimated, the amount of glycerol, glutamine, and carnosine increased, while glycogen and phenylalanine decreased. Overwintering cold-tolerant snails collected from a drained paddy field in November also showed increased glycerol in their bodies with decreasing glycogen concentration, compared to summer snails collected from a submerged field. Water content also decreased during the cold acclimation, although the water loss was minimal. These results indicate that the freshwater snail, P. canaliculata enhances cold hardiness by accumulation of some kinds of low molecular weight compounds in its body as some insects do. However, the actual function of each low molecular compound is still unknown.
福寿螺（Pomacea canaliculata）是一种入侵性淡水螺。它在冬季来临前增强其耐寒性。然而，软体动物耐寒性的生理机制尚不清楚，尤其是淡水软体动物。在本研究中，我们研究了福寿螺体内低分子量化合物、糖原和脂质的变化与耐寒性发展的关系。当对没有耐寒性的螺进行实验性冷驯化时，甘油、谷氨酰胺和肌肽的含量增加，而糖原和苯丙氨酸的含量降低。与从淹水田采集的夏季螺相比，11月从排水稻田采集的越冬耐寒螺体内甘油含量也增加，糖原浓度降低。冷驯化期间含水量也降低，尽管水分流失极少。这些结果表明，淡水螺福寿螺通过在体内积累某些低分子量化合物来增强耐寒性，就像一些昆虫那样。然而，每种低分子化合物的实际功能仍然未知。
