Abstract The genetic underpinnings of traits are rarely simple. Most traits of interest are instead the product of multiple genes acting in concert to determine the phenotype. This is particularly true for behavioral traits, like dispersal. Our investigation focuses on the genetic architecture of dispersal tendency in the red flour beetle, Tribolium castaneum. We used artificial selection to generate lines with either high or low dispersal tendency. Our populations responded quickly in the first generations of selection and almost all replicates had higher dispersal tendency in males than in females. These selection lines were used to create a total of 6 additional lines: F1 and reciprocal F1, as well as 4 types of backcrosses. We estimated the composite genetic effects that contribute to divergence in dispersal tendency among lines using line cross-analysis. We found variation in the dispersal tendency of our lines was best explained by autosomal additive and 3 epistatic components. Our results indicate that dispersal tendency is heritable, but much of the divergence in our selection lines was due to epistatic effects. These results are consistent with other life-history traits that are predicted to maintain more epistatic variance than additive variance and highlight the potential for epistatic variation to act as an adaptive reserve that may become visible to selection when a population is subdivided.

中文翻译：

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甲虫的行军：上位成分在 T. castaneum 的分散趋势中占主导地位

摘要 性状的遗传基础很少是简单的。大多数感兴趣的特征是多个基因协同作用以确定表型的产物。对于行为特征尤其如此，例如分散。我们的研究重点是红粉甲虫 Tribolium castaneum 中扩散趋势的遗传结构。我们使用人工选择来生成具有高或低分散趋势的线条。我们的种群在第一代选择中反应迅速，几乎所有重复在雄性中的扩散趋势都高于雌性。这些选择线用于创建总共 6 条附加线：F1 和互易 F1，以及 4 种类型的回交。我们使用系交叉分析估计了导致系间分散趋势差异的复合遗传效应。我们发现我们品系的分散趋势的变化最好用常染色体加性和 3 个上位成分来解释。我们的结果表明分散趋势是可遗传的，但我们选择线的大部分差异是由于上位效应。这些结果与其他生活史特征一致，这些特征被预测保持比加性方差更多的上位方差，并突出了上位变异作为适应性储备的潜力，当种群被细分时，选择可能变得可见。我们的结果表明分散趋势是可遗传的，但我们选择线的大部分差异是由于上位效应。这些结果与其他生活史特征一致，这些特征被预测保持比加性方差更多的上位方差，并突出了上位变异作为适应性储备的潜力，当种群被细分时，选择可能变得可见。我们的结果表明分散趋势是可遗传的，但我们选择线的大部分差异是由于上位效应。这些结果与其他生活史特征一致，这些特征被预测保持比加性方差更多的上位方差，并突出了上位变异作为适应性储备的潜力，当种群被细分时，选择可能变得可见。