Dissertation Research: Genetic Caste Determination in the Red Harvester Ant

红色收割机蚂蚁Pogonomyrmex barbatus的蚁群由一只多次交配的蚁后和许多不育的工蚁组成。在她的一生中，蚁后产卵，然后发育成工蚁或生殖器，即雄蚁和处女蚁。在大多数群居昆虫中，个体是发育成蚁后还是工蚁，取决于环境因素，如卵的营养或孵化温度。然而，我们对被称为微卫星的非编码DNA区域的分析表明，在红色收割机蚂蚁中，个体的基因型预测其种姓。这项拟议的研究将调查遗传种姓决定如何影响群体的发展。这项研究将测试与一只雄蜂交配或与多只相同基因雄蜂交配的蜂王是否只有雄蜂。监测蜂王和对它们的卵子进行基因分型将测试注定要成为生殖器的卵子是否会完成它们的发育。这篇论文项目将展示，在这一不寻常的种姓决定遗传系统下，一个群体如何调整其资源的分配，以适应繁殖和生长。这可能会揭示自然选择进化在群居昆虫群体上运作的新方式。

Colonies of the red harvester ant, Pogonomyrmex barbatus, consist of a single, multiply mated queen, and many sterile workers. Throughout her lifetime, the queen lays eggs that develop into workers, or reproductives, that is, males and virgin queens. In most social insects caste determination, whether an individual develops into a queen or a worker, is governed by environmental factors such as nutrition or incubation temperature of the eggs. However, our analyses of non-coding DNA regions called microsatellites revealed that in the red harvester ant, an individual's genotype predicts its caste. The proposed research will investigate how genetic caste determination affects a colony's development. The research will test whether queens that have mated with a single male, or multiple males of the same genotype, will have only males among their reproductives. Monitoring queens and genotyping their eggs will test whether eggs destined to become reproductives will not complete their development. This dissertation project will show how, under this unusual genetic system of caste determination, a colony can adjust the allocation of its resources to reproduction versus growth. This may reveal novel ways in which evolution by natural selection operates on colonies of social insects.