Department of Population Biology, Institute of Vertebrate Biology, Academy of Sciences of the Czech Republic, Brno, Czech Republic.
PLoS One. 2011;6(8):e23842. doi: 10.1371/journal.pone.0023842. Epub 2011 Aug 24.
The maternal manipulation hypothesis states that ectothermic females modify thermal conditions during embryonic development to benefit their offspring (anticipatory maternal effect). However, the recent theory suggests that the ultimate currency of an adaptive maternal effect is female fitness that can be maximized also by decreasing mean fitness of individual offspring. We evaluated benefits of temperature oviposition preferences in Alpine newts (Ichthyosaura [formerly Triturus] alpestris) by comparing the thermal sensitivity of maternal and offspring traits across a range of preferred oviposition temperatures (12, 17, and 22°C) and by manipulating the egg-predation risk during oviposition in a laboratory thermal gradient (12-22°C). All traits showed varying responses to oviposition temperatures. Embryonic developmental rates increased with oviposition temperature, whereas hatchling size and swimming capacity showed the opposite pattern. Maternal oviposition and egg-predation rates were highest at the intermediate temperature. In the thermal gradient, females oviposited at the same temperature despite the presence of caged egg-predators, water beetles (Agabus bipustulatus). We conclude that female newts prefer a particular temperature for egg-deposition to maximize their oviposition performance rather than offspring fitness. The evolution of advanced reproductive modes, such as prolonged egg-retention and viviparity, may require, among others, the transition from selfish temperature preferences for ovipositon to the anticipatory maternal effect.
母体操纵假说认为，变温动物的雌性在胚胎发育过程中会改变热环境，以使后代受益（预期的母体效应）。然而，最近的理论表明，适应性母体效应的终极货币是雌性适合度，通过降低个体后代的平均适合度也可以实现最大适合度。我们通过比较在一系列优选产卵温度（12、17 和 22°C）下的母体和后代特征的热敏感性，并通过在实验室热梯度（12-22°C）中操纵产卵期间的卵捕食风险，评估了高山蝾螈（Ichthyosaura [以前的 Triturus] alpestris）的温度产卵偏好的益处。所有特征都对产卵温度表现出不同的反应。胚胎发育速度随产卵温度的升高而增加，而孵化后个体大小和游泳能力则表现出相反的模式。母体产卵和卵捕食率在中间温度下最高。在热梯度中，尽管存在笼养的卵捕食者水甲虫（Agabus bipustulatus），但雌性仍在同一温度下产卵。我们得出的结论是，雌性蝾螈更喜欢特定的温度进行产卵，以最大限度地提高其产卵性能，而不是提高后代的适合度。高级生殖模式的进化，如延长卵保留和胎生，可能需要从自私的产卵温度偏好向预期的母体效应过渡。
