DISSERTATION RESEARCH: The evolutionary origin and genetics of color pattern diversity in Phyllobates poison frogs

论文研究：叶状毒蛙颜色图案多样性的进化起源和遗传学

• 批准号: 1702014
• 负责人: Marcus Kronforst
• 金额: $ 2.1万
• 依托单位: University of Chicago
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-06-01 至 2019-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1702014&HistoricalAwards=false
• 关键词: DISSERTATION; RESEARCH; evolutionary; origin; genetics

This project will identify the genes responsible for color pattern variation between different Poison-dart frogs. These frogs are well known for their brightly colored patterns, which serve as warning signals to deter potential predators. Within one small group of Poison-dart frogs (Phyllobates), vivid bright yellow colorations have independently evolved multiple times from dark, striped ancestors; in one species, different color morphs even occur within the same population. The researchers will take advantage of new genomic technologies and statistical analyses to identify the genes that differ between striped and solid-colored frogs. Results will provide critical insights on the genetic processes that underlie the independent evolution of color pattern variants in this group of frogs. The research will also reveal important information on the spread of beneficial genetic mutations within and across populations. In addition, the project will provide research opportunities for undergraduate students. Planned outreach includes public seminars and educational activities for elementary and middle school children. To pinpoint the genetic elements responsible for convergent evolution across Phyllobates species, this project takes advantage of ontogenetic, interspecific, and intraspecific variation in color pattern. First there is striking variation in color pattern between two pairs of closely related Phyllobates lineages, and within a population of Phyllobates aurotaenia from the upper San Juan River in Colombia. The researchers will use exon enrichment and next-generation sequencing to find loci that are highly differentiated between striped and solid-colored lineages, and statistically associated with color pattern variation within P. aurotaenia. Second, gene expression during coloration development will be studied using RNAseq, in order to identify genes that are up or down-regulated when changes in coloration occur throughout development. These two approaches will yield a set of putative loci behind color pattern variation in Phyllobates. The researchers will then use a combination of molecular phylogenetics and coalescent simulations to infer the evolutionary history of these loci, in order to shed light on the genetic mechanisms behind the convergent evolution of bright yellow coloration in this group of frogs.

该项目将鉴定导致不同毒箭蛙颜色图案差异的基因。这些青蛙以其色彩鲜艳的图案而闻名，这些图案可以作为警告信号来阻止潜在的捕食者。在一小群箭毒蛙（Phyllobates）中，鲜艳的亮黄色颜色是从深色条纹祖先独立进化而来的。在一个物种中，同一种群内甚至会出现不同的颜色变形。研究人员将利用新的基因组技术和统计分析来识别条纹青蛙和纯色青蛙之间的差异基因。结果将为这组青蛙颜色图案变异的独立进化背后的遗传过程提供重要的见解。该研究还将揭示有关有益基因突变在人群内部和人群之间传播的重要信息。此外，该项目还将为本科生提供研究机会。计划的外展活动包括针对中小学生的公共研讨会和教育活动。为了查明负责叶状动物物种趋同进化的遗传元件，该项目利用了颜色图案的个体发生、种间和种内变异。首先，两对密切相关的Phyllobates谱系之间以及来自哥伦比亚圣胡安河上游的Phyllobates aurotaenia种群内的颜色图案存在显着差异。研究人员将使用外显子富集和下一代测序来寻找条纹谱系和纯色谱系之间高度差异的基因座，并在统计上与 P. aurotaenia 内的颜色图案变异相关。其次，将使用 RNAseq 研究着色发育过程中的基因表达，以便识别在整个发育过程中发生着色变化时上调或下调的基因。这两种方法将产生叶状动物颜色图案变异背后的一组推定基因座。然后，研究人员将结合分子系统发育学和联合模拟来推断这些基因座的进化历史，以揭示这组青蛙亮黄色趋同进化背后的遗传机制。