Genetic and Phenotypic Variation in Foraging Behavior of African and European Honey Bees

非洲和欧洲蜜蜂觅食行为的遗传和表型变异主要研究者：Jennifer H. Fewell和Jon F. Harrison，亚利桑那州立大学综合生物学的一个基本问题是遗传变异如何与动物生存和繁殖策略的变异相关。回答这个问题的一种方法是确定动物种群之间行为差异的遗传基础，然后评估这些差异的生态影响。本项目研究了新热带非洲蜜蜂（Apis mellifera scutellata）和欧洲蜜蜂（Apis mellifera ligustica）觅食策略的差异。它解决了以下问题：(1)非洲和欧洲工蚁之间的遗传变异如何影响觅食策略，以及(2)工蚁觅食策略的变异如何影响两个亚种之间的群体增长率差异。种群水平的研究表明，非洲蜜蜂主要通过更快的群体增长和繁殖（蜂群）速度来竞争欧洲蜜蜂。因为蜜蜂是群居昆虫，这些群体策略的差异是由群体中个体工蜂行为的集体差异产生的。研究人员先前的研究表明，非洲和欧洲工蚁的主要行为差异在于觅食。非洲工蜂比欧洲工蜂更倾向于采集花粉。因为花粉是发育中的幼虫的主要食物来源，这种差异会对菌落生长产生深远的影响。本研究的第一个目的是了解产生花粉和花蜜觅食个体差异的机制。研究人员将验证这样一个假设，即非洲和欧洲采集者在资源选择上的差异是由他们对影响花粉收集的刺激的敏感性差异造成的。他们将确定共同抚养的非洲工蜂是否更容易对已知影响花粉觅食的刺激做出反应，并检查非洲和欧洲工蜂在已知与欧洲蜜蜂花粉觅食行为相关的基因组区域（数量性状位点或QTL）上的差异。初步数据还表明，非洲和欧洲工蚁在觅食过程中的工作努力不同，这种差异可能是由代谢能力的差异介导的。第二个目标是验证一个假设，即非洲和欧洲蜜蜂之间代谢率的差异是基于基因的，并且与资源偏好和觅食努力的差异有关。研究人员将比较共同抚养的非洲、欧洲和杂交工蜂的代谢率、觅食负荷大小和觅食率，以确定这些特征是如何遗传的。然后，将进行数量性状位点（QTL）定位，以确定影响飞行代谢率变异的基因组区域。这些将与已知的影响体型和偏好采集花粉与花蜜的基因座进行比较。第三个目标是确定个体觅食行为的变化是否会影响群体水平的生长率。研究人员将：(a)测量非洲和欧洲蜂箱中的花粉摄取率和蜂群生长率，以及(b)通过实验操作蜂箱中觅食者的基因型（非洲与欧洲），以测量觅食者基因型对雏鸟产量的影响。这项研究将行为学、生理学和遗传学结合起来，以更全面地了解产生复杂行为特征（如觅食）的近似机制。它还研究了个体行为差异对这些竞争亚种生态成功的影响。

Genetic and Phenotypic Variation in Foraging Behavior of African and European Honey BeesPrinciple Investigators: Jennifer H. Fewell and Jon F. Harrison, Arizona State UniversityA fundamental question in integrative biology is how genetic variation relates to variation in an animal's survival and reproductive strategies. One way to answer this is to determine the genetic basis for behavioral differences between animal populations and then assess the ecological effects of those differences. This project examines foraging strategy differences between neotropical African-derived (Apis mellifera scutellata) and European (Apis mellifera ligustica) honey bees. It addresses to the questions of: (1) how genetic variation between African and European workers influences foraging strategy, and (2) how variation in worker foraging strategy affects differences in colony growth rates between the two subspecies. Population-level research suggests that African honey bees out-compete European bees primarily through faster rates of colony growth and reproduction (swarming). Because honey bees are social insects, these differences in colony strategy are generated by collective differences in the behavior of the colony's individual workers. Prior research by the investigators suggests that a major behavioral difference between African and European workers is in foraging. African workers show a higher tendency than European workers to collect pollen. Because pollen is the primary food source for developing brood, this difference can have profound effects on colony growth. The first objective of this research is to understand the mechanisms producing individual differences in pollen and nectar foraging. The investigators will test the hypothesis that differences in resource choice between African and European foragers are driven by differences in their sensitivity to stimuli affecting pollen collection. They will determine whether co-fostered African workers respond more readily to stimuli known to affect pollen foraging, and examine differences between African and European workers in genomic regions (quantitative trait loci or QTL's) known to be associated with pollen foraging behavior in European bees.Preliminary data also suggest that African and European workers differ in work effort during foraging, and that this variation may be mediated by differences in metabolic capacity. The second objective is to test the hypothesis that variation in metabolic rate between African and European honey bees is genetically based, and is linked to differences in resource preference and foraging effort. The researchers will compare metabolic rates, foraging load sizes and foraging rates of co-fostered African, European and hybrid workers to determine how these traits are inherited. Then, quantitative trait locus (QTL) mapping will be performed to locate genomic regions influencing variation in flight metabolic rates. These will be compared to known loci affecting body size and preference for pollen versus nectar collection. The third objective is to determine whether variation in individual foraging behavior affects colony-level growth rates. The investigators will: (a) measure pollen intake rates and colony growth rates in African and European hives, and (b) experimentally manipulate the genotypes of the foragers in a hive (African versus European), to measure the effect of forager genotype on brood production. This research integrates behavior, physiology and genetics to generate a more complete understanding of the proximate mechanisms generating complex behavioral traits such as foraging. It also examines the consequences of individual behavioral differences on the ecological success of these competing subspecies.