Zoological Institute and Museum, University of Greifswald, Johann-Sebastian-Bach-Strasse 11 ⁄ 12, Greifswald, Germany.
J Evol Biol. 2012 Aug;25(8):1650-7. doi: 10.1111/j.1420-9101.2012.02547.x. Epub 2012 Jun 11.
Artificial selection is a powerful approach to unravel constraints on genetic adaptation. Although it has been frequently used to reveal genetic trade-offs among different fitness-related traits, only a few studies have targeted genetic correlations across developmental stages. Here, we test whether selection on increased cold tolerance in the adult stage increases cold resistance throughout ontogeny in the butterfly Bicyclus anynana. We used lines selected for decreased chill-coma recovery time and corresponding controls, which had originally been set up from three levels of inbreeding (outbred control, one or two full-sib matings). Four generations after having terminated selection, a response to selection was found in 1-day-old butterflies (the age at which selection took place). Older adults showed a very similar although weaker response. Nevertheless, cold resistance did not increase in either egg, larval or pupal stage in the selection lines but was even lower compared to control lines for eggs and young larvae. These findings suggest a cost of increased adult cold tolerance, presumably reducing resource availability for offspring provisioning and thereby stress tolerance during development, which may substantially affect evolutionary trajectories.
人工选择是一种强大的方法,可以揭示遗传适应的限制。尽管它经常被用来揭示不同与适应度相关的特征之间的遗传权衡,但只有少数研究针对发育阶段之间的遗传相关性。在这里,我们测试了在成年阶段增加耐寒性的选择是否会增加蝴蝶 Bicyclus anynana 在整个个体发育过程中的耐寒性。我们使用了经过选择以缩短低温昏迷恢复时间的品系和相应的对照品系,这些品系最初是由三个程度的近亲繁殖(杂交对照组、一个或两个全同胞交配)建立的。在终止选择后的四代,在 1 天大的蝴蝶(选择发生的年龄)中发现了对选择的反应。年长的成虫表现出非常相似但较弱的反应。然而,选择系的卵、幼虫或蛹期的耐寒性并没有增加,而卵和幼幼虫的耐寒性甚至比对照组的更低。这些发现表明增加的成年耐寒性存在成本,可能会降低为后代提供营养的资源可用性,从而降低发育过程中的压力耐受性,这可能会对进化轨迹产生重大影响。