Responses of the bed bug, Cimex lectularius, to temperature extremes and dehydration: levels of tolerance, rapid cold hardening and expression of heat shock proteins
Responses of the bed bug, Cimex lectularius, to temperature extremes and dehydration: levels of tolerance, rapid cold hardening and expression of heat shock proteins
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DOI：
10.1111/j.1365-2915.2009.00832.x
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发表时间：
2009-12-01
影响因子：
1.9
通讯作者：
Denlinger, D. L.
中科院分区：
文献类型：
--
作者：
Benoit, J. B.;Lopez-Martinez, G.;Denlinger, D. L.
这项研究的臭虫，温带臭虫，检查耐受性的成年女性极端温度和身体水分的损失。虽然臭虫的过冷却点（SCP）约为-20摄氏度，但所有臭虫都在直接暴露于-16摄氏度1小时后被杀死。因此，该物种不能忍受冷冻，并在远高于其SCP的温度下被杀死。无论是在4摄氏度的冷驯化2周，也没有脱水（15%的水含量损失）增强耐寒性。然而，臭虫具有快速冷硬化的能力，即暴露于0摄氏度1小时改善了它们随后对-14和-16摄氏度的耐受性。在应对热应激时，只有不到20%的虫子在46摄氏度下存活了1小时，几乎所有的虫子都在48摄氏度下死亡。脱水、30 ℃热习服2周和37 ℃快速热锻炼1 h均未能提高耐热性。编码两种热休克蛋白（Hsps），Hsp 70和Hsp 90的mRNA的表达在热应激、冷应激以及脱水和复水过程中升高。在脱水和复水过程中，Hsp 90的反应比Hsp 70更明显。我们的研究结果定义了臭虫对这些常见的温度和低湿度应力的耐受限度，并表明热休克蛋白在应对这些应力中的作用。
This study of the bed bug, Cimex lectularius, examines tolerance of adult females to extremes in temperature and loss of body water. Although the supercooling point (SCP) of the bed bugs was approximately -20 degrees C, all were killed by a direct 1 h exposure to -16 degrees C. Thus, this species cannot tolerate freezing and is killed at temperatures well above its SCP. Neither cold acclimation at 4 degrees C for 2 weeks nor dehydration (15% loss of water content) enhanced cold tolerance. However, bed bugs have the capacity for rapid cold hardening, i.e. a 1-h exposure to 0 degrees C improved their subsequent tolerance of -14 and -16 degrees C. In response to heat stress, fewer than 20% of the bugs survived a 1-h exposure to 46 degrees C, and nearly all were killed at 48 degrees C. Dehydration, heat acclimation at 30 degrees C for 2 weeks and rapid heat hardening at 37 degrees C for 1 h all failed to improve heat tolerance. Expression of the mRNAs encoding two heat shock proteins (Hsps), Hsp70 and Hsp90, was elevated in response to heat stress, cold stress and during dehydration and rehydration. The response of Hsp90 was more pronounced than that of Hsp70 during dehydration and rehydration. Our results define the tolerance limits for bed bugs to these commonly encountered stresses of temperature and low humidity and indicate a role for Hsps in responding to these stresses.