Kostál V, Zahradnícková H, Simek P, Zelený J
Biology Centre of the Academy of Sciences of the Czech Republic, Institute of Entomology, Branisovská 31, 370 05 Ceské Budejovice, Czech Republic.
J Insect Physiol. 2007 Jun;53(6):580-6. doi: 10.1016/j.jinsphys.2007.02.009. Epub 2007 Mar 7.
Overwintering adults of the spruce bark beetle, Ips typographus (L.) showed an unusually complex sugar/polyol cryoprotectant system. The major components of the multiple system were: glucose (177.6 mmolL(-1), March); trehalose (175.0 mmolL(-1), December); sorbitol (147.9 mmolL(-1), January); mannitol (81.2 mmolL(-1), March); and erythritol (40.7mmolL(-1), March) (in the parentheses, the maximum concentrations are shown and the month when they were reached). Other minor components were glycerol, fructose, threitol, myo-inositol, arabinitol and ribitol. Distinct seasonal patterns of accumulation/depletion in various components were found. Glycerol, trehalose and glucose started to accumulate first, during early autumn, when the air temperatures fluctuated between 20 and 0 degrees C, and diapause beetles continued in feeding. Glycerol was depleted, glucose remained stable and trehalose continued in accumulation during late autumn when the temperatures oscillated around 0 degrees C. During early winter severe frosts reaching -20 degrees C came, the beetles terminated their diapause and trehalose was partially depleted, while mannitol, sorbitol, fructose, threitol and erythritol started to accumulate. Cold weather continued also during late winter when the beetles remained quiescent. During this period, trehalose was re-accumulated, threitol and erythritol continued to increase, mannitol remained stable and sorbitol, fructose decreased. All cryoprotectans were finally cleared in the beetles which were spontaneously leaving bark during early spring. The seasonal maximum of total concentration of all cryoprotectants (578.2 mOsmol L(-1)) was reached in March. Such a concentration results in colligative depression of melting point of body fluids down by 1.08 degrees C only. It suggests that the potential cryoprotective effect of accumulated sugars and polyols was related rather to their non-colligative functions.
云杉八齿小蠹（Ips typographus (L.)）的越冬成虫表现出异常复杂的糖/多元醇抗冻保护系统。该多元系统的主要成分包括：葡萄糖（177.6 mmolL(-1)，3月）；海藻糖（175.0 mmolL(-1)，12月）；山梨醇（147.9 mmolL(-1)，1月）；甘露醇（81.2 mmolL(-1)，3月）；以及赤藓醇（40.7mmolL(-1)，3月）（括号内显示的是最大浓度以及达到该浓度的月份）。其他次要成分有甘油、果糖、苏糖醇、肌醇、阿拉伯糖醇和核糖醇。发现各成分存在明显的季节性积累/消耗模式。甘油、海藻糖和葡萄糖在初秋气温在20至0摄氏度之间波动且滞育甲虫仍在取食时首先开始积累。在深秋气温在0摄氏度左右波动时，甘油被消耗，葡萄糖保持稳定，海藻糖继续积累。初冬时严寒达到零下20摄氏度，甲虫终止滞育，海藻糖部分被消耗，而甘露醇、山梨醇、果糖、苏糖醇和赤藓醇开始积累。冬末天气依然寒冷，甲虫保持静止。在此期间，海藻糖重新积累，苏糖醇和赤藓醇继续增加，甘露醇保持稳定，山梨醇、果糖减少。所有抗冻保护剂最终在早春自发离开树皮的甲虫体内清除。所有抗冻保护剂总浓度的季节性最大值（578.2 mOsmol L(-1)）在3月达到。这样的浓度仅使体液熔点的依数性降低1.08摄氏度。这表明积累的糖和多元醇的潜在抗冻保护作用与其非依数性功能更为相关。
