Genetics of prezygotic reproductive isolation in natural populations of monk

描述（由申请人提供）：我们研究的长期目标是了解有性生殖生物自然种群中生殖隔离的遗传学和进化，即物种的起源。本文研究了猕猴花的两个姊妹种猕猴花（Mimulus lewisii）和猕猴花（M. cardinalis）野生种群的前合子生殖隔离遗传学。先前的研究表明，这些物种的同域种群之间的生殖隔离几乎完全由它们不同传粉者群体的保真度来调节。路易斯花由大黄蜂授粉，红雀花由蜂鸟授粉，它们对传粉者的偏好很大程度上取决于它们之间的花色差异。该项目的具体目标是：目标1。绘制大黄蜂授粉的路易斯花和蜂鸟授粉的红雀花4个主要数量性状位点（QTL）的高分辨率遗传和物理图谱。包含这些qtl的物理区域将被测序和注释。目标2。构建高分辨率的近等基因系（hrNILs），分别分析路易斯花和红衣花的4个主要基因座的颜色差异。hrNILs将近似于单基因替代，并将适用于现场实验。目标3。在自然共感区的普通园林田间试验中，通过直接观察hrNILs，确定4个花色位点及其组合效应在路易斯花和红衣花之间的总合子前生殖隔离所占的比例。4个花色位点（15种可能组合）对传粉者偏好的影响将通过hrNILs阵列和“祖先”路易斯菊的田间试验进行评估。最后一项实验将直接比较大黄蜂和蜂鸟对“祖先”路易斯分枝杆菌表型、路易斯分枝杆菌背景下的4位点hrNIL和衍生的红雀分枝杆菌的偏好。所有15个hrNIL组合的传粉者访问表型，结合亲本M. lewisii和M. cardinalis的数据，将使我们能够估计所有4个位点对生殖隔离的个体和总体影响。我们的预期是，绝大多数（约75%）的生殖隔离将归因于这4个花色位点。这些实验将使我们第一次了解任何自然系统中前合子生殖隔离的多位点遗传学。

DESCRIPTION (provided by applicant): The long-term goal of our research is to understand the genetics and evolution of reproductive isolation in natural populations of sexually-reproducing organisms: i.e., the origin of species. This proposal focuses on the genetics of prezygotic reproductive isolation in wild populations of two sister species of monkeyflower, Mimulus lewisii, and M. cardinalis. Previous studies have demonstrated that reproductive isolation between sympatric populations of these species is mediated almost exclusively by the fidelity of their different pollinator guilds. M. lewisii is pollinated by bumblebees, M. cardinalis is pollinated by hummingbirds, and pollinator preference depends strongly on flower color differences between them. The Specific Aims of this project are to: Aim 1. Produce high-resolution genetic and physical maps of the 4 major quantitative trait loci (QTL) controlling differences in flower color between bumblebee-pollinated M. lewisii and hummingbird-pollinated M. cardinalis. Physical regions containing these QTLs will be sequenced an annotated. Aim 2. Construct and characterize high-resolution near-isogenic lines (hrNILs) for each of the 4 major loci controlling differences in flower color between M. lewisii and M. cardinalis. hrNILs will approximate single-gene substitutions, and will be suitable for field experiments. Aim 3. Determine the proportion of the total prezygotic reproductive isolation between M. lewisii and M. cardinalis attributable to each of the 4 flower color loci, and to their combinatorial effects, by direct observation of hrNILs in common garden field experiments in areas of natural sympatry. The effect of each of the 4 flower color loci (in all 15 possible combinations) on pollinator preference will be assessed in field experiments with arrays of hrNILs and the "ancestral" M. lewisii. A final experiment will directly compare the preference of bumblebees and hummingbirds for the "ancestral" M. lewisii phenotype, a 4-locus hrNIL in a M. lewisii background, and the derived M. cardinalis. The pollinator visitation phenotypes of all 15 hrNIL combinations, combined with data from parental M. lewisii and M. cardinalis, will allow us to estimate the individual and aggregate effect of all 4 loci on reproductive isolation. Our expectation is that the vast majority (>75%) of reproductive isolation in sympatry will be attributable to just these 4 flower color loci. These experiments will provide our first glimpse into the multi-locus genetics of prezygotic reproductive isolation in any natural system. PUBLIC HEALTH RELEVANCE: The long-term goal of our research is to understand the genetics and evolution of reproductive isolation in natural populations of sexually reproducing organisms: i.e., the origin of species. All of the biodiversity on Earth, including the origin of humans, is a result of the process of speciation.