Kotiaho Janne S, Simmons Leigh W, Hunt John, Tomkins Joseph L
Department of Zoology, University of Western Australia, Nedlands, Western Australia 6009, Australia.
Am Nat. 2003 Jun;161(6):852-9. doi: 10.1086/375173. Epub 2003 May 7.
Recently, doubt has been cast on studies supporting good genes sexual selection by the suggestion that observed genetic benefits for offspring may be confounded by differential maternal allocation. In traditional analyses, observed genetic sire effects on offspring phenotype may result from females allocating more resources to the offspring of attractive males. However, maternal effects such as differential allocation may represent a mechanism promoting genetic sire effects, rather than an alternative to them. Here we report results from an experiment on the horned dung beetle Onthophagus taurus, in which we directly compare genetic sire effects with maternal effects that are dependent on sire phenotype. We found strong evidence that mothers provide more resources to offspring when mated with large-horned males. There were significant heritabilities for both horn length and body size, but when differential maternal effects were controlled, the observed estimates of genetic variance were greatly reduced. Our experiment provides evidence that differential maternal effects may amplify genetic effects on offspring traits that are closely related to fitness. Thus, our results may partly explain the relatively high coefficients of additive genetic variation observed in fitness-related traits and provide empirical support for the theoretical argument that maternal effects can play an important role in evolution.
最近，对于支持优质基因性选择的研究产生了质疑，有人提出，观察到的后代遗传益处可能会因母体分配差异而混淆。在传统分析中，观察到的父本基因对后代表型的影响可能源于雌性将更多资源分配给有吸引力的雄性的后代。然而，诸如差异分配等母体效应可能代表了一种促进父本基因效应的机制，而非是其替代机制。在此，我们报告了一项关于有角蜣螂（Onthophagus taurus）的实验结果，在该实验中，我们直接比较了父本基因效应与依赖于父本表型的母体效应。我们发现有力证据表明，与长角雄性交配时，母亲会为后代提供更多资源。角长度和体型都存在显著的遗传力，但当控制了差异母体效应后，观察到的遗传方差估计值大幅降低。我们的实验提供了证据，表明差异母体效应可能会放大对与适应性密切相关的后代性状的基因效应。因此，我们的结果可能部分解释了在与适应性相关的性状中观察到的相对较高的加性遗传变异系数，并为母体效应在进化中可发挥重要作用这一理论观点提供了实证支持。
