Data from: Vitamins, stress and growth: the availability of antioxidants in early life influences the expression of cryptic genetic variation

Environmental inputs during early development can shape the expression of phenotypes, which has long-lasting consequences in physiology and life history of an organism. Here, we study whether experimentally manipulated availability of dietary antioxidants, vitamins C and E, influences the expression of genetic variance for antioxidant defence, endocrine signal and body mass in yellow-legged gull chicks using quantitative genetic models based on full siblings. Our experimental study in a natural population reveals that the expression of genetic variance in total antioxidant capacity in plasma increased in chicks supplemented with vitamins C and E despite the negligible effects on the average phenotype. This suggests that individuals differ in their ability to capture and transport dietary antioxidants or to respond to these extra resources, and importantly, this ability has a genetic basis. Corticosterone level in plasma and body mass were negatively correlated at the phenotypic level. Significant genetic variance of corticosterone level appeared only in control chicks nonsupplemented with vitamins, suggesting that the genetic variation of endocrine system, which transmits environmental cues to adaptively control chick development, appeared in stressful conditions (i.e. poor antioxidant availability). Therefore, environmental inputs may shape evolutionary trajectories of antioxidant capacity and endocrine system by affecting the expression of cryptic genetic variation.个体发育早期的环境输入可塑造表型表达，这对生物体的生理状态与生活史具有持久影响。 本研究基于全同胞（full siblings）数量遗传模型（quantitative genetic models），探究实验调控膳食抗氧化剂——维生素C与维生素E的可获得性，是否会影响黄腿鸥（yellow-legged gull）雏鸟的抗氧化防御、内分泌信号与体质量的遗传方差表达。 我们在自然种群中开展的实验研究显示，尽管补充维生素C、E对雏鸟的平均表型影响可忽略不计，但血浆总抗氧化能力的遗传方差表达在补充维生素的雏鸟群体中显著升高。 这表明个体间在摄取、转运膳食抗氧化剂，或是响应额外抗氧化资源的能力上存在差异；尤为关键的是，该能力具有遗传基础。 血浆皮质酮（Corticosterone）水平与体质量在表型层面呈负相关。 仅在未补充维生素的对照组雏鸟中，血浆皮质酮水平才表现出显著的遗传方差，这表明：将环境信号传递以适应性调控雏鸟发育的内分泌系统，其遗传变异仅在胁迫条件（即抗氧化剂可获得性不足的环境）下才会显现。 因此，环境输入可通过影响隐蔽遗传变异（cryptic genetic variation）的表达，塑造抗氧化能力与内分泌系统的演化轨迹。