Density-dependent prophylaxis in the mealworm beetle Tenebrio molitor L-(Coleoptera: Tenebrionidae):: cuticular melanization is an indicator of investment in immunity
Density-dependent prophylaxis in the mealworm beetle Tenebrio molitor L-(Coleoptera: Tenebrionidae):: cuticular melanization is an indicator of investment in immunity
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DOI：
10.1098/rspb.2000.0984
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发表时间：
2000-01-22
影响因子：
4.7
通讯作者：
Siva-Jothy, MT
中科院分区：
文献类型：
--
作者：
Barnes, AI;Siva-Jothy, MT
如果维持病原体抗性需要付出成本，那么当发病风险较高时，预计会对该性状进行更高的投资。发病风险升高的一种情况是同种密度增加。本文报道了黄粉虫病原体抗性和免疫功能中密度依赖性多型性的研究结果。与单独饲养的甲虫相比，以高幼虫密度饲养的甲虫在接触普通昆虫病原真菌时表现出较低的死亡率，并且角质层黑化程度更高。角质层黑化程度是抵抗力的有力指标，无论饲养密度如何，深色甲虫都比浅色甲虫更具抵抗力。不同饲养密度之间酚氧化酶（昆虫免疫反应的关键酶）水平没有差异。结果表明，黄飞虱的病原体抗性在表型上是可塑的，这表明维持这一性状的成本很高。
If there are costs involved with the maintenance of pathogen resistance, then higher investment in this trait is expected when the risk of pathogenesis is high. One situation in which the risk of pathogenesis is elevated is at increased conspecific density. This paper reports the results of a study of density-dependent polyphenism in pathogen resistance and immune function in the mealworm beetle Tenebrio molitor. Beetles reared at high larval densities showed lower mortality when exposed to a generalist entomo-pathogenic fungus and a higher degree of cuticular melanization than those reared solitarily The degree of cuticular melanization was a strong indicator of resistance, with darker beetles being more resistant than lighter ones regardless of rearing density. No differences were found between rearing densities in the levels of phenoloxidase, an enzyme key to the insect immune response. The results show that pathogen resistance is phenotypically plastic in T. molitor suggesting that the maintenance of this trait is costly.