CAREER: Ecological Speciation and Heterogeneous Genomic Differentiation in Hybridizing Haplodiploids

据估计，地球上有900万种物种，具有不同的习性和外观。为了解释这种多样性，科学家们研究了新物种是如何形成的，并描述了它们之间的差异是如何积累的。大多数科学家都认为，对不同生境的适应经常会引发新物种的形成。然而，物种形成的遗传原因和后果仍然是一个谜。这个项目利用了两种松树喂养的害虫，这是“在行为中捕获”的物种形成。虽然它们之间有许多差异，但在自然界中，红头松叶蜂和白松叶蜂在低水平上杂交。这表明物种的形成并不完全。对不同松树的适应似乎是减少这些物种之间基因交换的关键因素。实验室杂交和田间试验将用于确定不同的松树适应性的遗传区域。这些结果应该揭示这些差异如何影响野生这些物种之间的基因交换率。这项工作将为保护生物多样性和防治害虫提供必要的知识。此外，该项目将开发综合研究/教学项目，为公众和不同的本科生提供科学经验。 了解生态物种形成的遗传基础需要确定基因型，生殖隔离和全基因组遗传分化之间的联系。该项目利用这对杂交叶蜂物种，不同的主机使用特性和生殖障碍。首先，QTL定位方法将把遗传变异与寄主偏好和寄主性能性状的变异联系起来。第二，现场诱捕实验将连接主机偏好表型成人栖息地隔离。第三，田间试验操纵宿主植物和宿主使用性状，将宿主性能性状与适合度和生殖隔离联系起来。第四，对这些物种的重叠和孤立的成对种群进行全基因组重新测序，将揭示遗传分化的人口统计学历史和模式。补充教育工作将培训公民科学家捕捉和识别叶蜂，并培训非STEM学生筛选样本并解释诊断PCR检测。总之，这些数据将用于评估杂交的空间和时间变化。此外，STEM学生将参与连接基因型、表型、健身、生殖隔离和分化的田间和实验室实验。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

There are an estimated nine million species on earth, with diverse habits and appearances. To explain this diversity, scientists examine how new species form and describe how differences accumulate between them. Most scientists agree that adaptation to different habitats frequently initiates the formation of new species. The genetic causes and consequences of species formation, however, remain a mystery. This project takes advantage of two pine tree-feeding insect pests that are "caught in the act" of species formation. Although there are many differences between them, the redheaded-pine sawfly and the white-pine sawfly interbreed at low levels in nature. This suggests that species formation is not quite complete. Adaptation to different pines appears to be a key factor that reduces gene exchange between these species. Laboratory crosses and field experiments will be used to identify the genetic regions responsible for different pine adaptations. The results should reveal how these differences affect rates of gene exchange between these species in the wild. This work will provide essential knowledge for preserving biodiversity and combatting pests. Additionally, this project will develop integrated research/teaching projects that provide scientific experiences for the public and diverse undergraduates. Understanding the genetic basis of ecological speciation requires identifying links among genotypes, reproductive isolation, and genome-wide genetic differentiation. This project takes advantage of this pair of hybridizing sawfly species that differ in host-use traits and reproductive barriers. First, a QTL mapping approach will link genetic variation to variation in host-preference and host-performance traits. Second, a field trapping experiment will link host-preference phenotypes to adult habitat isolation. Third, a field experiment manipulates both the host plants and host-use traits to link host-performance traits to fitness and reproductive isolation. Fourth, full-genome re-sequencing of overlapping and isolated pairs of populations of these species will reveal the demographic history of divergence and patterns of genetic differentiation. The complementary educational efforts will train citizen scientists to trap and identify sawflies and non-STEM students to screen samples and interpret a diagnostic PCR assay. Together, these data will be used to evaluate spatial and temporal variation in hybridization. Additionally, STEM students will participate in field and lab experiments that connect genotype, phenotype, fitness, reproductive isolation, and differentiation.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.