Metabolism of the sub-Antarctic caterpillar Pringleophaga marioni during cooling, freezing and thawing
Metabolism of the sub-Antarctic caterpillar Pringleophaga marioni during cooling, freezing and thawing
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亚南极毛毛虫 Pringleophaga marioni 在冷却、冷冻和解冻过程中的代谢
DOI：
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发表时间：
2004
影响因子：
2.8
通讯作者：
S. Chown
中科院分区：
文献类型：
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作者：
B. Sinclair;C. Klok;S. Chown
虽然存在昆虫冷冻存活过程的一般模型，但很少有研究直接研究冷却，冷冻和解冻过程中的生理过程，没有这些模型仍然是假设的。在这里，我们使用开放式呼吸测量法来研究耐冷冻的亚南极毛虫Pringleophaga marioni Viette（鳞翅目：Tineidae）在冷却，冷冻和解冻期间的代谢，并比较暴露于非致命（-5.8 ° C）和致命（-6.0 ° C，之后毛虫会濒死几天，-18 ° C，之后毛虫完全没有反应）冷冻应激的动物。我们发现在-0.6 ±0.1°C时代谢率大幅下降（与冷冻无关），并计算出该断点处的Q10为2.14×103。该断点与临界热最小值（CTmin）一致，并被假设为后者的代谢表现，可能是Na+/K+-ATP酶泵的故障。这提供了细胞水平的过程与组织和整个生物体水平的CTmin作用观察之间的合理联系。毛虫在-4.6至0.1 °C下冷冻，冷冻时具有可检测的代谢。解冻后，代谢率低于冷冻前的测量值。解冻后的代谢率没有不同的温度，没有杀死毛虫，这表明死亡率可能是在有机体，而不是细胞，组织水平的过程中的故障的结果。
SUMMARY Although general models of the processes involved in insect survival of freezing exist, there have been few studies directly investigating physiological processes during cooling, freezing and thawing, without which these models remain hypothetical. Here, we use open-flow respirometry to investigate the metabolism of the freeze-tolerant sub-Antarctic caterpillar Pringleophaga marioni Viette (Lepidoptera: Tineidae) during cooling, freezing and thawing and to compare animals exposed to non-lethal (–5.8°C) and lethal (–6.0°C, after which caterpillars are moribund for several days, and –18°C, after which caterpillars are completely unresponsive) freezing stress. We found a large decrease in metabolic rate (that is not associated with freezing) at– 0.6±0.1°C and calculated a Q10 of 2.14×103 at this breakpoint. This breakpoint is coincident with the critical thermal minimum (CTmin) and is hypothesised to be a metabolic manifestation of the latter, possibly a failure of the Na+/K+-ATPase pump. This provides a plausible link between processes at the cellular level and observations of the action of the CTmin at tissue and whole-organism levels. Caterpillars froze at –4.6±0.1°C and had detectable metabolism when frozen. Post-thaw, metabolic rates were lower than pre-freezing measurements. Post-thaw metabolic rates did not differ between temperatures that did and did not kill the caterpillars, which suggests that mortality may be a result of a breakdown in processes at the organismal, rather than cellular, level of organisation.