Mechanisms promoting speciation with gene flow in host-specialized haplodiploids

宿主特异性单倍二倍体中基因流促进物种形成的机制

• 批准号: 2348574
• 负责人: Catherine Linnen
• 金额: $ 133.57万
• 依托单位: University of Kentucky Research Foundation
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2024
• 资助国家: 美国
• 起止时间: 2024-04-01 至 2028-03-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2348574&HistoricalAwards=false
• 关键词: Mechanisms; promoting; speciation; gene; flow

One of the longest running debates in evolutionary biology is whether new species can form while exchanging genes with one another. Gene exchange is thought to make species formation difficult because it mixes up genetic backgrounds. This mixing prevents the buildup of differences between species. Nevertheless, genetic data tell us that many species do exchange genes in nature. The goal of this project is to understand how some species can withstand gene exchange. To do so, this project focuses on a pair of pine-feeding insect species that are common pests in the eastern United States. These two species are adapted to different pine species and have exchanged genes throughout their history. By focusing on immature and adult life stages and both sexes, this project will produce a more complete picture of how adaptation to different environments produces new species. By filling gaps in our understanding of how new species arise, this work will deepen our understanding of the world around us. This knowledge will help us preserve biodiversity and combat pests. Additionally, the researchers will use their project to develop educational materials for teaching genetics and evolution to first-year Biology students. This project will also provide opportunities for dozens of students to participate in authentic scientific research. Such experiences can help us retain talented students in STEM disciplines. Evolutionary theory predicts that speciation with gene flow is difficult, yet empirical data indicate such divergence scenarios are common in nature. To reconcile these seemingly contradictory findings, the proposed work takes advantage of an experimentally tractable pair of pine sawfly species (Neodiprion lecontei and N. pinetum) that are adapted to different pines and have exceptional genomic resources, extensive complementary data, and a history of divergence with gene flow. First, larval diet manipulations of the focal species and their reciprocal male and female hybrids will be used to quantify reproductive isolation on all combinations of host plants and to evaluate the role of phenotypic plasticity in promoting speciation with gene flow. Second, larval transcriptomes of the two species and their reciprocal first-generation hybrids reared on both parental hosts will be used to uncover how divergent transcriptional responses to larval diet contribute to host adaptation and gene misexpression in hybrids. Third, quantitative trait locus mapping in second-generation hybrid males reared on both parental hosts will be used to describe the genetic architecture of host-dependent and host-independent hybrid viability, larval performance, and adult male morphology. Because this work provides intuitive examples of the complexity of phenotypic variation and mechanisms through which natural selection produces new species, data from the proposed work will be used to develop a case study and scientist spotlights for use in introductory Biology courses and to fuel student-driven research.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.

进化生物学中运行时间最长的辩论之一是，新物种在彼此之间交换基因时是否可以形成。人们认为基因交换使物种形成变得困难，因为它混合了遗传背景。这种混合阻止了物种之间的差异。然而，遗传数据告诉我们，许多物种确实在自然界交换基因。该项目的目的是了解某些物种如何承受基因交换。为此，该项目着重于美国东部常见害虫的一对喂养昆虫。这两种物种适应了不同的松树，并在其整个历史上都交换了基因。通过专注于不成熟和成人生活阶段以及两个性别，该项目将为适应不同环境产生新物种而产生更完整的了解。通过填补我们对新物种如何出现的理解的空白，这项工作将加深我们对周围世界的理解。这些知识将有助于我们保护生物多样性和战斗害虫。此外，研究人员将利用他们的项目开发教育材料，以向第一年生物学学生讲授遗传学和进化。该项目还将为数十名学生提供参与真实科学研究的机会。这样的经历可以帮助我们将才华横溢的学生留在STEM学科中。 进化论预测，具有基因流的物种是困难的，但是经验数据表明这种差异情景在本质上很普遍。为了调和这些看似矛盾的发现，拟议的工作利用了一对可触及的松树锯蝇物种（Neodiprion lecontei和N. pinetum），它们适合于不同的松树，并具有非凡的基因组资源，广泛的互补数据，以及与基因流相差的历史。首先，将使用焦点物种及其相互男性和女性杂种的幼虫饮食操纵来量化宿主植物的所有组合的生殖隔离，并评估表型可塑性在促进基因流量促进形态中的作用。其次，这两个物种的幼虫转录组及其在两个亲本宿主上饲养的相互第一代杂种将用于揭示对幼虫饮食的不同转录反应如何有助于在杂交中宿主的宿主和基因。第三，在两个父母宿主上饲养的第二代杂种雄性中的定量性状基因座图将用于描述宿主依赖性和独立于宿主的杂种生存能力，幼虫性能和成人男性形态的遗传结构。因为这项工作提供了自然选择产生新物种的表型变化和机制的复杂性的直观示例，因此将使用提议的工作中的数据来开发案例研究和科学家聚焦在入门生物学课程中的使用，并促进学生驱动的研究。这一奖项反映了NSF的法定任务和审查的范围，这是通过评估的范围来进行的。