Genotype x environment interaction and the evolution of sexually-selected traits

基因型与环境的相互作用和性选择性状的进化雄性性特征如交配信号的遗传变异的存在仍然是进化生物学中的一个主要问题。 雌性的选择往往倾向于夸大的交配信号，从而有望大大减少遗传变异，但最近的调查表明，在许多物种中仍然存在大量的变异。 这个问题已经在一个声音的pyralid蛾，小蜡蛾（Achroia grisella），其中男性广播的超声波交配歌曲吸引女性高达几米远。 回放实验表明，女性较小的蜡蛾更喜欢男性的歌曲，区分几个关键功能，和育种实验表明大量的遗传变异，和遗传力，这些歌曲的功能。 额外的育种实验和测试与近交系表明，生活史字符和男性歌曲的吸引力之间的遗传权衡不负责维持这种变化。 也就是说，有吸引力的歌手更大，不需要更长的时间来达到这个尺寸，生存时间更长，每晚和一生中花更多的时间唱歌。 另一方面，随时间和空间的环境变化，结合基因型和环境之间的相互作用，可能有助于观察到的雄性歌曲吸引力的遗传变异：某些品系在有利的环境条件下发育时表现出上级吸引力，但在压力下表现出明显的下降，而其他品系在有利的环境中表现出适度的表现，但在压力下表现出很少的减少;也就是说，没有一种遗传变异体在所有环境中都表现出上级性能。 然而，这些研究结果迄今仅限于高度近交或人工选择的实验室种群的观察，和环境变化和基因型x环境的相互作用，以保持在自然群体中的遗传变异的实际意义是未知的。 在这个项目中，研究人员将以一种重要的方式扩展上述研究，以确定：（1）对环境梯度的反应范围;（2）实际发生在该领域的环境变化可能会保持男性歌曲吸引力的遗传变异水平。 特别是，他们将确定遗传变异的水平是否反映了一个群体所经历的环境变异的数量，以及在有利和压力环境中表现出最大吸引力的遗传变异是否发生。 两位共同首席研究员还将确定女性对男性信号偏好的变化以及女性偏好性状对环境变化的反应是否会导致男性歌曲吸引力的遗传变异。 这种可能性将通过一个平行的分子遗传学（数量性状位点，QTL）分析近交系，他们将检查影响男性歌曲和女性偏好性状的基因之间的协方差。总的来说，该项目强调基因和环境之间复杂的相互作用，可以塑造动物的行为。 对GEI的关注将有助于引导生物学家的注意力转向更现实的交配行为研究，远离关于信号和偏好的“类型学”思维倾向。 QTL分析将代表这一强大的遗传工具的第一个应用程序，用于调查负责交配选择性状的种内差异的遗传基础。 此外，该项目将涉及本科生和研究生以及博士后科学家，他们将接受声学通信和进化遗传学研究的培训。 参加N. S.F.本科生研究经验（REU）项目的学生将在夏季由堪萨斯大学生态与进化生物学系提供与拟议研究相关的独立研究。 蛾从各种线将提供给实验室在各种本科生物课。

Genotype x Environment Interaction and the Evolution of Sexually Selected TraitsThe presence of genetic variation for male sexual traits such as mating signals remains a major problem in evolutionary biology. Female choice often favors exaggerated mating signals and is thereby expected to reduce genetic variation greatly, yet recent surveys indicate that substantial variation remains in many species. This problem has been addressed in an acoustic pyralid moth, the lesser wax moth (Achroia grisella), in which males broadcast an ultrasonic mating song attractive to females up to several meters distant. Playback experiments show that female lesser wax moths prefer male songs that are distinguished by several key features, and breeding experiments demonstrate substantial genetic variance, and heritability, for these song features. Additional breeding experiments and tests with inbred lines indicate that genetic tradeoffs between life history characters and male song attractiveness are not responsible for maintaining this variance. That is, attractive singers are larger, do not take longer to attain that size, survive longer, and spend more time singing on nightly and lifetime bases. On the other hand, environmental variation over space and time, combined with interactions between genotypes and the environment, may contribute to the genetic variance observed for male song attractiveness: Certain lines exhibit superior attractiveness when developing under a favorable environmental regime but show marked declines under stress, while other lines exhibit only modest performance in favorable environments but show little reduction in stress; that is, no one genetic variant exhibits the superior performance in all environments. However, these findings have thus far been restricted to observations of highly inbred or artificially selected laboratory populations, and the actual significance of environmental variation and genotype x environment interaction for maintaining genetic variance in natural populations is unknown. In this project researchers will extend the aforementioned studies in an important way by determining whether: (1) the range of responses to environmental gradients; and (2) the environmental variation that actually occur in the field are likely to maintain the levels of genetic variance observed for male song attractiveness. In particular, they will determine whether the level of genetic variance reflects the amount of environmental variation a population has experienced, and whether genetic variants that exhibit maximum attractiveness in both favorable and stressful environments occur. The two co-Principal Investigators will also determine whether variation in female preference for male signals, and the response of the female preference trait to environmental variation, contribute to genetic variance for male song attractiveness. This possibility will be augmented via a parallel molecular genetic (quantitative trait locus, QTL) analysis of inbred lines in which they will examine the covariance between genes that influence male song and female preference traits. Overall, the project emphasizes the complex interplay between genes and the environment that can shape animal behavior. The focus on GEI will help direct the attention of biologists toward more realistic studies of mating behavior and away from tendencies toward 'typological' thinking with regard to signals and preferences. The QTL analysis will represent one of the first applications of this powerful genetic tool for investigating the genetic bases of intra-specific differences in traits responsible for mate choice. In addition, the project will involve undergraduate and graduate students and postdoctoral scientists who will be trained in the study of acoustic communication and evolutionary genetics. Students attending the N.S.F. Research Experiences for Undergraduates (REU) program offered during the summer by the Department of Ecology and Evolutionary Biology at the University of Kansas will do independent studies related to the proposed research. Moths from the various lines will be made available for laboratories in various undergraduate biology classes.