The role of the gut in insect chilling injury: cold-induced disruption of osmoregulation in the fall field cricket, Gryllus pennsylvanicus
The role of the gut in insect chilling injury: cold-induced disruption of osmoregulation in the fall field cricket, Gryllus pennsylvanicus
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DOI：
10.1242/jeb.051540
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发表时间：
2011-03-01
影响因子：
2.8
通讯作者：
Sinclair, Brent J.
中科院分区：
文献类型：
--
作者：
MacMillan, Heath A.;Sinclair, Brent J.
为了预测气候变化对昆虫分布和丰度的影响，需要清楚地了解关键温度限制的机制。在昆虫中，肌肉功能的丧失和冷诱导损伤的发生以前与肌肉静息电位的丧失相关。为了确定这种功能丧失的原因，我们测量了冷暴露对肌肉组织，血淋巴和秋季田野蟋蟀，Gryllus pennaculicus的消化道中的离子和水稳态的影响，在暴露于0摄氏度，造成冷害和死亡。低温暴露对肌肉渗透平衡影响不大，但通过血淋巴和肠道之间的相互作用使肌肉离子平衡电位降低。血淋巴体积下降了84%，而在冷暴露肠道水含量上升，以可比的方式。这种水含量的上升是由于未能维持跨肠壁的渗透平衡，这导致在冷暴露期间Na+、Ca2+和Mg2+大量迁移到消化道中。这种内稳态的丧失可能是导致冷敏感昆虫物种中冷诱导的肌肉兴奋性丧失和冷害进展的主要机制。
To predict the effects of changing climates on insect distribution and abundance, a clear understanding of the mechanisms that underlie critical thermal limits is required. In insects, the loss of muscle function and onset of cold-induced injury has previously been correlated with a loss of muscle resting potential. To determine the cause of this loss of function, we measured the effects of cold exposure on ion and water homeostasis in muscle tissue, hemolymph and the alimentary canal of the fall field cricket, Gryllus pennsylvanicus, during an exposure to 0 degrees C that caused chilling injury and death. Low temperature exposure had little effect on muscle osmotic balance but it dissipated muscle ion equilibrium potentials through interactions between the hemolymph and gut. Hemolymph volume declined by 84% during cold exposure whereas gut water content rose in a comparable manner. This rise in water content was driven by a failure to maintain osmotic equilibrium across the gut wall, which resulted in considerable migration of Na+, Ca2+ and Mg2+ into the alimentary canal during cold exposure. This loss of homeostasis is likely to be a primary mechanism driving the cold-induced loss of muscle excitability and progression of chilling injury in chill-susceptible insect species.