RUI: Quantifying larval behavior to reconcile genetic connectivity with biophysical model predictions

RUI：量化幼虫行为以协调遗传连接与生物物理模型预测

• 批准号: 1130072
• 负责人: Patrick Krug
• 金额: $ 35.9万
• 依托单位: California State L A University Auxiliary Services Inc.
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-09-01 至 2016-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1130072&HistoricalAwards=false
• 关键词: RUI; Quantifying; larval; behavior; reconcile

Dispersal is a critical life-history trait linking ecological and evolutionary processes. Transport of planktonic larvae affects colonization success and population persistence for benthic animals, and influences genetic subdivision of populations, local adaptation, and speciation. However, recent studies question the long-held assumption that pelagic larval duration (PLD) determines how far larvae are advected. This has applied significance, as oceanographic models used to predict exchange among marine protected areas often use PLD as the key larval parameter. The investigators' data for Caribbean gastropods show genetic breaks that are not congruent with model predictions, and levels of structure that are inconsistent with larval lifespan, highlighting a need for new theory. Intellectual merits: This research will integrate molecular and larval ecology to test the link between dispersal and larval duration in a phylogenetic framework, and determine whether Individual Based Models (IBMs) accurately predict exchange for Caribbean reef ecosystems. The PI will collect multi-locus genetic data and quantify larval behavior for 14 related, ecologically similar species of sea slugs with PLDs from 0-30 days. The PI predicts that larval behavior explains why some species are under- or over-dispersed relative to their PLD; this work will reveal key parameters needed for biophysical-coupling models to predict connectivity for coastal invertebrates. The proposal will address 3 inter-related objectives: (1) Are genetic connectivity estimates from mtDNA and nuclear markers congruent, and consistent with model predictions? Data for mitochondrial and nuclear loci will be used to test for selection on mtDNA, estimate rates of gene flow and times of divergence, and assess levels of connectivity within each species. Matrices of model-predicted exchange will be compared with genetic similarity matrices to test whether breaks in gene flow occur where predicted. (2) Are genetic connectivity and PLD correlated? More broadly, the PI will test the assumption that larval period determines dispersal, using comparative methods in a phylogenetic framework to correct for effects of relatedness among species. The PI will compare models of trait evolution with Bayesian Markov chain Monte Carlo (MCMC) methods to determine if gene flow is correlated or uncorrelated with PLD, using a molecular phylogeny and multi-locus genetic data. (3) Does larval behavior explain genetic structure in species with long PLD? At least two of the focal species selected for this study are under-dispersed, with genetically isolated demes despite a 30-day PLD. Conversely, at least one short-PLD species has no genetic structure over large regions of the Caribbean. The PI will build on past work quantifying larval behavior to ask if species-specific differences in larval swimming facilitate local retention, making species deviate from expected connectivity patterns. The PI will also test whether pre-competent larvae respond to habitat cues in a way that influences dispersal, as occurs in fish. This work will reconcile life-history theory, oceanographic models, and genetics by mechanistically explaining breaks in connectivity; the results will deepen our understanding of how larval behavior can determine the pace of divergence among populations. Broader impacts: Student training is a major thrust of this proposal, based at a Hispanic-serving institution. Funding will support undergraduate and M.S. students from under-represented ethnic groups (5 of 9 current research students are Latino or black). Krug will publish with graduate and undergraduate student co-authors, and work to place students in Ph.D. programs; in the last funding period, 7 papers had student co-authors and two minority students were accepted into Ph.D. programs. Through established partnerships, the PI will host one area high school teacher and 3 students in the first year of funding for research experiences. Continued outreach through COSEE-west will allow the PI-led group to increase content knowledge for K-12 science teachers using examples from marine ecology and evolution. Public outreach will include bimonthly segments on the local NPR affiliate radio station (KPCC), and lectures at the K-12 and community college level through programs aimed to broaden diversity in the science and technology workforce.

分散是连接生态和进化过程的重要生活史特征。浮游生物幼虫的迁移影响底栖动物的定殖成功和种群持久性，并影响种群的遗传细分、局部适应和物种形成。然而，最近的研究对长期以来的假设提出了质疑，即远洋幼虫期（PLD）决定了幼虫平流的距离。这具有重要的应用意义，因为用于预测海洋保护区之间交换的海洋学模型通常使用PLD作为关键的幼虫参数。研究人员对加勒比海腹足类动物的数据显示，基因断裂与模型预测不一致，结构水平与幼虫寿命不一致，这突出了对新理论的需求。智力优势：本研究将整合分子生态学和幼虫生态学，在系统发育框架内测试扩散和幼虫持续时间之间的联系，并确定基于个体的模型（IBMs）是否准确预测加勒比海珊瑚礁生态系统的交换。PI将收集多位点遗传数据，并量化14种生态相似的具有pld的海蛞蝓在0-30天内的幼虫行为。PI预测幼虫的行为解释了为什么一些物种相对于它们的PLD分散不足或过度；这项工作将揭示用于预测沿海无脊椎动物连通性的生物物理耦合模型所需的关键参数。该提案将解决3个相互关联的目标：(1)mtDNA和核标记的遗传连通性估计是否一致，并且与模型预测一致？线粒体和核位点的数据将用于测试mtDNA的选择，估计基因流动率和分化时间，并评估每个物种内的连通性水平。模型预测的交换矩阵将与遗传相似矩阵进行比较，以测试基因流动是否发生在预测的地方。(2)遗传连通性与PLD是否相关？更广泛地说，PI将测试幼虫期决定扩散的假设，使用系统发育框架中的比较方法来纠正物种间亲缘关系的影响。PI将使用分子系统发育和多位点遗传数据，将性状进化模型与贝叶斯马尔可夫链蒙特卡罗（MCMC）方法进行比较，以确定基因流是否与PLD相关。(3)幼虫行为能否解释长PLD物种的遗传结构？本研究选择的至少两个焦点物种分散不足，尽管有30天的PLD，但仍有遗传隔离的巢。相反，在加勒比海的大片地区，至少有一种短pld物种没有遗传结构。PI将建立在过去量化幼虫行为的工作基础上，以询问幼虫游泳的物种特异性差异是否有助于局部保留，使物种偏离预期的连接模式。PI还将测试能力前的幼虫是否会对栖息地的线索做出反应，从而影响扩散，就像鱼类那样。这项工作将通过机械地解释连接中断来调和生命史理论、海洋学模型和遗传学；研究结果将加深我们对幼虫行为如何决定种群分化速度的理解。更广泛的影响：学生培训是该提案的主要推动力，以西班牙裔服务机构为基础。资金将支持来自少数族裔的本科生和硕士学生（目前9名研究生中有5名是拉丁裔或黑人）。克鲁格将与研究生和本科生共同发表论文，并努力安排学生攻读博士学位；在上一个资助期内，有7篇论文有学生共同作者，两名少数民族学生被博士项目录取。通过已建立的伙伴关系，PI将在第一年资助一名地区高中教师和三名学生进行研究经验。通过COSEE-west的持续推广将使pi领导的小组能够使用海洋生态学和进化的例子为K-12科学教师增加内容知识。公共宣传将包括每两个月在美国国家公共电台（NPR）的地方分支电台（KPCC）播出，并通过旨在扩大科学和技术劳动力多样性的项目，在K-12和社区大学进行讲座。