Quantitative genetics of immunity and life history under different photoperiods.
Quantitative genetics of immunity and life history under different photoperiods.
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不同光周期下免疫和生活史的数量遗传学。
DOI：
10.1038/hdy.2011.125
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发表时间：
2012
期刊：
影响因子：
3.8
通讯作者：
Hammerschmidt K
中科院分区：
文献类型：
--
作者：
Hammerschmidt K
具有复杂生活史的昆虫应在幼虫发育期间优化成熟时的年龄和大小。当栖息在季节性环境中时，生物体的繁殖期有限，并面临着根本性的决定：在季节后期成熟的个体必须要么以较小的规模繁殖，要么提高其生长速度。增加昆虫的生长速度是昂贵的，因为更高的青少年死亡率，降低成年人的生存或增加的易感性，寄生细菌和病毒通过受损的免疫功能。环境变化如季节性也可以改变数量遗传结构。在这里，我们探讨了数量遗传学的生活史和免疫性状的实验诱导的两个季节性环境中的蟋蟀bimaculatus。季节性影响生活史，但不影响免疫表型。日长递减条件下的个体发育较慢，生长较大。我们发现了充足的加性遗传方差和遗传力的免疫组件（血细胞密度，proPhenoloxidase活性，对粘质沙雷氏菌的抗性），和生活史特征，年龄和大小在成熟。尽管性状之间存在遗传协方差，但G的结构与生活史和免疫性状之间基于遗传的权衡不一致（例如，估计生长速率和血细胞密度之间存在强正遗传相关性）。然而，条件进化性支持这样的观点：遗传协方差结构限制了个体性状独立进化的能力。我们没有发现由实验诱导的季节性引起的G× E相互作用的证据。
Insects with complex life-cycles should optimize age and size at maturity during larval development. When inhabiting seasonal environments, organisms have limited reproductive periods and face fundamental decisions: individuals that reach maturity late in season have to either reproduce at a small size or increase their growth rates. Increasing growth rates is costly in insects because of higher juvenile mortality, decreased adult survival or increased susceptibility to parasitism by bacteria and viruses via compromised immune function. Environmental changes such as seasonality can also alter the quantitative genetic architecture. Here, we explore the quantitative genetics of life history and immunity traits under two experimentally induced seasonal environments in the cricket Gryllus bimaculatus. Seasonality affected the life history but not the immune phenotypes. Individuals under decreasing day length developed slower and grew to a bigger size. We found ample additive genetic variance and heritability for components of immunity (haemocyte densities, proPhenoloxidase activity, resistance against Serratia marcescens), and for the life history traits, age and size at maturity. Despite genetic covariance among traits, the structure of G was inconsistent with genetically based trade-off between life history and immune traits (for example, a strong positive genetic correlation between growth rate and haemocyte density was estimated). However, conditional evolvabilities support the idea that genetic covariance structure limits the capacity of individual traits to evolve independently. We found no evidence for G× E interactions arising from the experimentally induced seasonality.