Data from: Disentangling genetic and prenatal maternal effects on offspring size and survival

Organizational processes during prenatal development can have long-term effects on an individual’s phenotype. Because these early developmental stages are sensitive to environmental influences, mothers are in a unique position to alter their offspring’s phenotype by differentially allocating resources to their developing young. However, such prenatal maternal effects are difficult to disentangle from other forms of parental care, additive genetic effects, and/or other forms of maternal inheritance, hampering our understanding of their evolutionary consequences. Here we used divergent selection lines for high and low prenatal maternal investment and their reciprocal line crosses in a precocial bird—the Japanese quail (Coturnix japonica)—to quantify the relative importance of genes and prenatal maternal effects in shaping offspring phenotype. Maternal but not paternal origin strongly affected offspring body size and survival throughout development. Although the effects of maternal egg investment faded over time, they were large at key life stages. Additionally, there was evidence for other forms of maternal inheritance affecting offspring phenotype at later stages of development. Our study is among the first to successfully disentangle prenatal maternal effects from all other sources of confounding variation and highlights the important role of prenatal maternal provisioning in shaping offspring traits closely linked to fitness.

产前发育过程中的组织调控过程，可对个体的表型（phenotype）产生长期影响。由于这些早期发育阶段对环境影响极为敏感，母本可通过差异化分配发育后代所需资源，从而独特地改变子代的表型。然而，此类产前母本效应很难与其他形式的亲代抚育、加性遗传效应（additive genetic effects）以及其他类型的母系遗传相区分，这阻碍了我们对其进化后果的理解。本研究以早成鸟——日本鹌鹑（Coturnix japonica）为研究对象，利用针对高、低产前母本投入的趋异选择品系及其正反交品系，量化了基因与产前母本效应在塑造子代表型中的相对重要性。母本而非父本的来源，显著影响了子代在整个发育过程中的体型大小与存活率。尽管母本产卵投入的效应会随时间推移逐渐减弱，但在关键生活史阶段其影响仍十分显著。此外，有证据表明，在发育后期，其他形式的母系遗传同样会对子代表型产生影响。本研究是首批成功将产前母本效应与所有其他混淆变异来源区分开来的研究之一，并强调了产前母本供给在塑造与适合度紧密相关的子代性状中的重要作用。