SG: RUI: Paralogous paths to gaining anthocyanin pigmentation in Chilean monkeyflowers

这项研究的目的是了解生物体某一特征的重复进化更有可能是通过相同的基因变化发生的，还是通过不同的基因变化发生的。生物学中的一个主要挑战是了解特定的基因和基因突变如何影响生物体在其环境中发挥作用的能力。在某些种类的植物中，一种称为“花青素”的红色色素已经反复进化，可能是因为这些色素为植物提供了好处。在花朵中，鲜艳的红色色素有助于吸引蜂鸟等传粉者。这些色素还可以作为抗氧化剂，帮助保护植物免受压力诱导的细胞损伤。这项研究将确定在一组猕猴花(Mimulus)中三次重复获得红色花青素色素所使用的基因类型和突变。它将解决进化(或人工选择，在作物育种的情况下)可能有多大灵活性的问题。有没有多种可以互换的、同样好的方法来获得某种特征，或者每种不同的方法获得花青素色素都有自己独特的一套成本和收益？该项目将为本科生研究团队提供高级遗传和分子培训。此外，每年将为在传统学校苦苦挣扎的年轻人提供一个来自当地替代高中的有前途的学生的实习机会。该项目的主要目标是识别导致三个物种中每一个花瓣花青素获得的特定基因和突变类型，这三个物种分别是铜绿微囊藻、变色微囊藻和南美微囊藻。目的1验证R2R3MYB基因家族的特定基因是否通过激活来重复进化，或者不同的MYB基因在花瓣花青素(LA)的进化获得方面是否在功能上是等价的和可互换的。研究人员将使用转基因转化，随后进行表型和适合度分析，以确定(I)相同的基因是否对铜绿微囊藻和南方分支杆菌反复获得的解放军负责，以及(Ii)铜绿微囊藻和变色微囊藻中的两个不同的原因基因在功能上是否相等和可互换。Aim 2将测试更广泛的基因组区域(pla1和plA2)是否在功能上相等。研究人员将使用渐渗法将+解放军等位基因(以及相关的基因组区域)转移到不同的解放军背景中。杂交种将通过表型和适合度分析进行筛选，以确定pla1和plA2区域是否相同或功能不同。目标3将测试解放军的进化是由单一分子机制还是由突变类型组成。将+pla编码序列和-pla调控序列组合在一起的嵌合转基因将被用来确定因果突变在三个进化时间点上是编码还是顺式调控：种群内、物种内和物种之间。精细结构图谱将被用来识别核苷酸水平的突变变化。

The goal of this research is to understand whether the repeated evolution of a trait of an organism is more likely to occur through the same genetic change or through different genetic changes. A major challenge in biology is to understand how specific genes and genetic mutations affect the ability of organisms to function in their environments. In some groups of plants, a red pigmentation called "anthocyanin" has repeatedly evolved, probably because of the benefits that those pigments provide to plants. In flowers, brightly-colored red pigments help attract pollinators such as hummingbirds. The pigments also serve as antioxidants which help protect plants from stress-induced cell damage. This research will identify the types of genes and mutations used in three repeated gains of red anthocyanin pigmentation in a group of monkeyflowers (Mimulus). It will address the question of how flexible evolution (or artificial selection, in the case of crop breeding) might be. Are there multiple interchangeable, equally good ways of achieving a certain trait, or does each different route to the gain of anthocyanin pigmentation come with its own unique set of costs and benefits? The project will provide advanced genetic and molecular training for teams of undergraduate researchers. In addition, one internship will be provided each year to a promising student from the local alternative high school for youth who struggle in traditional schools.A primary goal of this project is to identify the specific genes and types of mutations responsible for the gain of petal anthocyanin in each of three species, M. cupreus, M. l. variegatus, and M. naiandinus. Aim 1 will test whether evolution is repeated through activation of a specific gene of the R2R3 MYB gene family, or alternatively, whether different MYB genes are functionally equivalent and interchangeable with respect to the evolutionary gain of Petal Lobe Anthocyanin (PLA). The researchers will use transgenic transformation, followed by phenotype and fitness assays, to determine (i) whether the same gene is responsible for the repeated PLA gain in M. cupreus versus M. naiandinus, and (ii) whether the two distinct causal genes in M. cupreus and M.I. variegatus are functionally equivalent and interchangeable. Aim 2 will test whether the broader genomic regions (pla1 and pla2) are functionally equivalent. The researchers will use introgression to move the +PLA alleles (along with the associated genomic regions) into different -PLA backgrounds. The hybrids will be screened by phenotype and fitness assays to determine if the pla1 and pla2 regions are either equivalent or functionally distinct. Aim 3 will test whether PLA evolution consists of a single molecular mechanism or type of mutation. Chimeric transgenes, which combine +PLA coding sequence with -PLA regulatory sequence and vice versa, will be used to determine whether the causal mutation is coding or cis-regulatory for three evolutionary timepoints: within-population, within-species, and between species. Fine structure mapping will be used to identify the mutational changes at the nucleotide level.