Data from: Environmental stress linked to consumption of maternally derived carotenoids in brown trout embryos (Salmo trutta)

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 (Salmo trutta). 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.

鲑科鱼类（salmonid）鱼卵呈现的黄、橙或红色，源自母体传递的类胡萝卜素，目前此类物质的具体功能尚未被充分阐明。本研究以褐鳟（Salmo trutta）为研究对象，探讨了天然获取的类胡萝卜素作为母体环境效应在胚胎发育过程中的重要作用。我们从野生雌性褐鳟体内采集鱼卵，对其类胡萝卜素含量进行定量分析；采用完全析因繁殖设计开展体外受精，以区分母体效应与父体效应，并将3278枚胚胎分别置于不同应激条件下单体饲养至孵化。研究发现显著的父本效应，该效应揭示了胚胎存活率与孵化时间存在加性遗传方差。母本效应的影响强度是父本效应的5.4倍，这表明母体环境效应在决定胚胎应激耐受性方面发挥着关键作用。在我们靶向检测的8种色素分子中，仅虾青素、玉米黄质（二者均会影响鱼卵红色度）以及叶黄素的检出量高于置信阈值。未观察到未受精卵的类胡萝卜素含量与胚胎死亡率或孵化时间之间存在显著关联。但在应激处理过程中，类胡萝卜素的消耗水平与半同胞组的胚胎存活率呈负相关，且该因素可解释约14%的母体环境效应方差。综上，我们认为母体传递的类胡萝卜素参与了胚胎应对环境应激的能力调控，但胚胎对有机污染的初始易感性主要由其他因素决定。