Wilkins Laetitia G E, Marques da Cunha Lucas, Glauser Gaëtan, Vallat Armelle, Wedekind Claus
Department of Ecology and Evolution Biophore, University of Lausanne Lausanne Switzerland.
Department of Environmental Sciences Policy & Management University of California Berkeley CA USA.
Ecol Evol. 2017 Jun 2;7(14):5082-5093. doi: 10.1002/ece3.3076. eCollection 2017 Jul.
The yellow, orange, or red colors of salmonid eggs are due to maternally derived carotenoids whose functions are not sufficiently understood yet. Here, we studied the significance of naturally acquired carotenoids as maternal environmental effects during embryo development in brown trout (). We collected eggs from wild females, quantified their egg carotenoid content, fertilized them in vitro in full-factorial breeding blocks to separate maternal from paternal effects, and raised 3,278 embryos singly at various stress conditions until hatching. We found significant sire effects that revealed additive genetic variance for embryo survival and hatching time. Dam effects were 5.4 times larger than these sire effects, indicating that maternal environmental effects play an important role in determining embryo stress tolerance. Of the eight pigment molecules that we targeted, only astaxanthin, zeaxanthin (that both affected egg redness), and lutein were detected above our confidence thresholds. No strong link could be observed between carotenoid content in unfertilized eggs and embryo mortality or hatching timing. However, the consumption of carotenoids during our stress treatment was negatively correlated to embryo survival among sib groups and explained about 14% of the maternal environmental variance. We conclude that maternally derived carotenoids play a role in the ability of embryos to cope with environmental stress, but that the initial susceptibility to the organic pollution was mainly determined by other factors.
鲑鱼卵的黄色、橙色或红色是由于母体来源的类胡萝卜素，其功能尚未得到充分了解。在此，我们研究了自然获得的类胡萝卜素作为母体环境效应在褐鳟胚胎发育过程中的重要性。我们从野生雌鱼收集鱼卵，量化其鱼卵类胡萝卜素含量，在全因子育种区组中进行体外受精以区分母体效应和父体效应，并在不同应激条件下单独饲养3278个胚胎直至孵化。我们发现了显著的父体效应，揭示了胚胎存活率和孵化时间的加性遗传方差。母体效应比这些父体效应大5.4倍，表明母体环境效应在决定胚胎应激耐受性方面起着重要作用。在我们所针对的8种色素分子中，只有虾青素、玉米黄质（两者都影响鱼卵红色）和叶黄素的检测值高于我们的置信阈值。在未受精卵中的类胡萝卜素含量与胚胎死亡率或孵化时间之间未观察到强烈联系。然而，在我们的应激处理期间类胡萝卜素的消耗与同胞组中的胚胎存活率呈负相关，并解释了约14%的母体环境方差。我们得出结论，母体来源的类胡萝卜素在胚胎应对环境应激的能力中发挥作用，但对有机污染的初始易感性主要由其他因素决定。
