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

这项研究的目的是了解生物体特征的重复进化是否更有可能通过相同的遗传变化或通过不同的遗传变化发生。生物学的一个主要挑战是了解特定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。在某些植物群中，一种被称为“花青素”的红色色素不断进化，可能是因为这些色素对植物有好处。在花中，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，帮助保护植物免受胁迫引起的细胞损伤。这项研究将确定在一组猴花（Mimulus）中三次重复获得红色花青素色素的基因和突变类型。它将解决如何灵活的进化（或人工选择，在作物育种的情况下）的问题。是否有多种可互换的，同样好的方法来实现某种特性，或者每种不同的途径来获得花青素色素沉着都有其独特的成本和收益？该项目将为本科研究人员团队提供先进的遗传和分子培训。此外，每年还将为当地另一所高中的有前途的学生提供一次实习机会，这些学生都是在传统学校奋斗的年轻人。该项目的主要目标是确定三个物种中负责花瓣花青素获得的特定基因和突变类型，M. cupreus，M. L. variegatus和M.奈安迪努斯。目的1将测试是否通过R2 R3 MYB基因家族的特定基因的激活来重复进化，或者替代地，不同的MYB基因是否在功能上等同并且相对于花瓣叶花色素苷（PLA）的进化增益是可互换的。研究人员将使用转基因转化，然后进行表型和适应性测定，以确定（i）是否相同的基因是负责重复的PLA增益在M。cupreus与M. naiandinus，以及（ii）是否在M.铜和M.I. variegatus在功能上是等同的并且可互换。目标2将测试更广泛的基因组区域（pla 1和pla 2）是否在功能上等同。研究人员将使用基因渗入将+PLA等位基因（沿着相关的基因组区域）移动到不同的-PLA背景中。将通过表型和适应性试验筛选杂交体，以确定pla 1和pla 2区域是否等同或功能不同。目标3将测试PLA进化是否由单一分子机制或突变类型组成。嵌合转基因，其将联合收割机+PLA编码序列与-PLA调节序列组合，反之亦然，将用于确定因果突变在三个进化时间点是编码还是顺式调节：群体内、物种内和物种间。精细结构图谱将用于鉴定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.