DISSERTATION RESEARCH: Surviving habitat loss: Physiological and evolutionary basis underlying tolerance to deforestation

论文研究：幸存的栖息地丧失：容忍毁林的生理和进化基础

• 批准号: 1404527
• 负责人: Elizabeth Hadly
• 金额: $ 2.09万
• 依托单位: Stanford University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-06-01 至 2015-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1404527&HistoricalAwards=false
• 关键词: DISSERTATION; RESEARCH; Surviving; habitat; loss

Tropical deforestation reshapes biological communities, benefitting some species, while pushing others towards local extinction. This research will examine the ecological and evolutionary underpinnings of tolerance to deforestation by focusing on the genetics of two closely related Central American frog species. Along with climate change and disease, habitat loss is pushing numerous amphibian species towards extinction. Understanding the biochemical basis for thermal adaptation is a crucial area of research given the multifaceted ways that humans are heating local, regional, and global climates. This research will inform conservation outcomes by providing insight into the reasons that some species are capable of bucking this global trend. The project also will involve the training of a graduate student and undergraduates, including individuals from groups that are underrepresented in the sciences.The researchers will study two species in the genus Craugastor that differ in their tendency to live in forested and deforested areas. Their previous research identified thermal tolerance as the primary factor explaining whether a species can survive in warmer, deforested areas. They will subject both species to forest- or pasture-like temperature regimes, and then uses Illumina-based RNA sequencing to test whether interspecific differences in constitutive expression and capacity to upregulate thermal stress tolerance genes (e.g., heat shock proteins) correspond to habitat affinity. They can thus begin to assess how gene regulation facilitates survival in deforested habitats. While differential expression may facilitate survival, structural differences (i.e., in protein coding sequence) also likely play a role. They will compare sequence data between species to scan for signatures of adaptation by employing both conventional molecular evolutionary tests for positive selection (i.e., dN/dS), as well as developing a novel structure-based approach that examines how changes at the DNA level are expected to alter protein stability at warm temperatures. Using protein homology modeling and RNA sequence data, they will test the hypothesis that proteins in the deforestation-tolerant species exhibit increased thermal stability. Because conventional methods of testing for positive selection are prone to false negatives, the use of a structure based, hypothesis-testing framework will substantially increase the detection of thermal adaptation. This study will place ecological changes caused by human activity in a macroevolutionary context, and provide a specific structural hypothesis to detect thermal adaption in an increasingly warm, human-dominated biosphere.

热带森林砍伐重塑了生物群落，使某些物种受益，同时将其他物种推向局部灭绝。这项研究将通过关注两种密切相关的中美洲青蛙物种的遗传学来研究对森林砍伐的耐受性的生态和进化基础。除气候变化和疾病外，栖息地丧失正在推动许多两栖动物灭绝。鉴于人类正在加热本地，区域和全球气候的多方面方式，了解热适应的生化基础是至关重要的研究领域。这项研究将通过洞悉某些物种能够逆转这一全球趋势的原因来为保护结果提供信息。该项目还将涉及对研究生和本科生的培训，包括来自科学中人数不足的人的个人。研究人员将在CRAUGASTOR属中研究两个物种，这些物种的生活在森林和森林砍伐地区的趋势不同。他们以前的研究将热耐受性确定为解释物种是否可以在温暖，森林砍伐地区生存的主要因素。它们将使两种物种都处于森林或牧场状的温度状态，然后使用基于Illumina的RNA测序来测试本种间表达的种间差异和上调上调热应激耐受性基因（例如热激蛋白）的能力是否与栖息地亲和力相对应。因此，他们可以开始评估基因调节如何促进森林砍伐栖息地的生存。尽管差异表达可能促进生存，但结构差异（即在蛋白质编码序列中）也可能起作用。他们将通过使用传统的分子进化测试进行阳性选择（即DN/DS），并开发一种基于结构的新方法，以研究如何在温度温度下改变蛋白质稳定性，从而比较物种之间的序列数据与扫描适应的签名以扫描适应性的签名。使用蛋白质同源性建模和RNA序列数据，他们将检验以下假设：易砍伐植物的蛋白质表现出增加的热稳定性。由于常规的测试阳性选择方法容易造成虚假负面因素，因此使用基于结构的使用，假设测试框架将大大增加热适应性的检测。这项研究将在宏观进化的环境中放置由人类活动引起的生态变化，并提供特定的结构假设，以检测日益温暖，以人为主导的生物圈的热适应。