Measuring the heritability of sex ratio in a social insect

动物社会行为如何进化的理论代表了进化生态学的一个基本问题，它假设社会行为受基因的影响。这一关键假设很少得到验证，对社会特征背后的基因也知之甚少。研究人员对性状进行人工选择的实验，结合现代遗传和基因组技术，可以帮助确定和识别这些性状的基因。在未来，我的团队将寻求在熊蜂（Bombus terrestris）中进行这样的实验，使用性别比例（新蜂王与雄性的比例）作为感兴趣的社会特征。虽然进化模型很好地预测了群居昆虫的性别比例，但与其他社会特征一样，对其遗传基础知之甚少。然而，要进行这项工作，我们首先需要确定性别比例确实是由遗传变异所支撑的，即是可遗传的，因为不可遗传的性状不能对自然或人工选择做出反应。因此，在拟议的工作中，我试图测量B性别比的遗传力。terrestris。这个物种是唯一适合拟议的工作，因为它的简单，每年的社会，其顺从实验室饲养和繁殖，并存在日益复杂的遗传信息，其基因组结构。我将通过比较女王女儿和母亲的性别比例来衡量遗传性。女儿和母亲性别比例之间的正相关将建立遗传性（正式估计为该相关回归系数的两倍）。除了解决进化生态学中的一个基本问题外，这一提议也是新颖的，因为以前没有在任何社会昆虫中测量过性别比例的遗传性。出于这个原因，也因为它应该导致一个未来的项目，也将是新颖的和基本的，拟议的研究应该大大推进该领域。

Theories for how social behaviour evolves in animals, which represents a fundamental issue in evolutionary ecology, assume that social behaviour is influenced by genes. This critical assumption has rarely been tested, and very little is known about the genes underlying social traits. Experiments in which researchers subject traits to artificial selection, combined with modern genetic and genomic techniques, can help pinpoint and identify genes for these traits. In future, my group seeks to conduct such experiments in the bumble bee Bombus terrestris, using sex ratio (the ratio of new queens to males) as the social trait of interest. Although the value of the sex ratio in social insects is well predicted by evolutionary models, as with other social traits very little is known about its genetic basis. However, to conduct this work we first need to establish that sex ratio is indeed underpinned by genetic variation, i.e. is heritable, since non-heritable traits cannot respond to either natural or artificial selection. In the proposed work I therefore seek to measure the heritability of sex ratio in B. terrestris. This species is uniquely suited to the proposed work because of its simple, annual societies, its amenability to laboratory rearing and breeding, and the existence of increasingly sophisticated genetic information on its genomic architecture. I will measure heritability by comparing the sex ratios produced by daughter queens with those produced by their mothers. A positive association between daughter and maternal sex ratios will establish heritability (which is formally estimated as twice the regression coefficient of this association). As well as addressing a fundamental issue in evolutionary ecology, this proposal is novel, because the heritability of sex ratio has not previously been measured in any social insect. For this reason, and because it should lead to a future project that would also be novel and fundamental, the proposed research should substantially advance the field.