Effects of inbreeding and temperature stress on life history and immune function in a butterfly
Effects of inbreeding and temperature stress on life history and immune function in a butterfly
复制标题
DOI：
10.1111/jeb.12064
复制
发表时间：
2013-03-01
影响因子：
2.1
通讯作者：
Fischer, K.
中科院分区：
文献类型：
--
作者：
Franke, K.;Fischer, K.
理论预测，在环境胁迫下，由于隐性有害等位基因的表达增加，近交抑制应该更加明显。如果是这样，近亲繁殖的种群可能特别容易受到环境变化的影响。在此背景下，本文研究了温度胁迫对热带双环蝶近交的影响及其与近交的相互作用。我们采用全因子设计，采用三个近交水平（F=0/0.25/0.38）和三个温度处理（在1,27或39℃下暴露2h）。尽管近交水平相对较低，但在蛹质量、蛹时间、胸质量、腹部脂肪含量、卵孵化成功率和繁殖力等方面均有显著的近交抑制。然而，抗逆性性状（耐热性、免疫功能）不受近亲繁殖的影响，与温度处理的相互作用几乎不存在。因此，我们没有发现近亲繁殖个体对环境压力的敏感性增加的支持，并怀疑这种模式仅限于更恶劣的条件。我们的温度处理明显施加了胁迫，显著降低了寿命、繁殖力、卵孵化成功率和血细胞数量，但脂肪含量、蛋白质含量和溶菌酶活性未受影响。除蛹时间、蛋白质含量和酚氧化酶（PO）活性外，其他性状均存在差异。相关分析显示，除其他外，脂肪含量与溶菌酶活性之间存在权衡关系，脂肪含量与其他一些性状之间存在负相关。我们强调，在得出更普遍的结论之前，需要更多的数据来研究近亲繁殖、温度变化和性别差异对昆虫免疫功能的影响。
Theory predicts that inbreeding depression should be more pronounced under environmental stress due to an increase in the expression of recessive deleterious alleles. If so, inbred populations may be especially vulnerable to environmental change. Against this background, we here investigate effects of inbreeding, temperature stress and its interactions with inbreeding in the tropical butterfly Bicyclus anynana. We use a full-factorial design with three levels of inbreeding (F=0/0.25/0.38) and three temperature treatments (2h exposure to 1, 27 or 39 degrees C). Despite using relatively low levels of inbreeding significant inbreeding depression was found in pupal mass, pupal time, thorax mass, abdomen fat content, egg hatching success and fecundity. However, stress resistance traits (heat tolerance, immune function) were not affected by inbreeding and interactions with temperature treatments were virtually absent. We thus found no support for an increased sensitivity of inbred individuals to environmental stress, and suspect that such patterns are restricted to harsher conditions. Our temperature treatments evidently imposed stress, significantly reducing longevity, fecundity, egg hatching success and haemocyte numbers, while fat content, protein content and lysozyme activity remained unaffected. Males and females differed in all traits measured except pupal time, protein content and phenoloxidase (PO) activity. Correlation analyses revealed, among others, a trade-off between PO and lysozyme activity, and negative correlations between fat content and several other traits. We stress that more data are needed on the effects of inbreeding, temperature variation and sexual differences on insect immune function before more general conclusions can be drawn.