Collaborative Research: Behavioral and Genetic Mechanisms for Frequency-Dependent Survival and Mating Advantage in Guppies

在基因组时代，越来越明显的是，与生物（包括人类）的健康、寿命和生育能力相关的大多数特征都受到遗传变异（多态性）的影响。尽管人们对绘制和描述相关基因有着浓厚的兴趣，但维持遗传变异的过程通常是未知的。一个原因是直接的实验研究在人类中是不可能的，在大多数模式生物中是困难和昂贵的。为了解决这个问题，需要在自然和实验室环境中研究更容易处理的物种。野生孔雀鱼表现出动物中最显著的多态性之一（雄性颜色模式变异），被认为是通过交配和生存优势来维持稀有或不常见的颜色类型。交配优势似乎是由于雌性对不寻常雄性的性反应，而生存优势似乎是由于对常见颜色类型的选择性捕食。该项目将阐明这些模式背后的行为和遗传机制。研究将探讨(1)稀有类型的交配优势的行为机制；(2)掠食性鳉鱼对稀有类型和常见类型的行为反应；(3)当孔雀鱼对新的性刺激和环境刺激作出反应时，大脑基因表达的变化。具体的结果包括确定(1)雌性孔雀鱼是否对罕见的雄性孔雀鱼有特殊的偏好，(2)先前对颜色类型的经验是否会影响捕食者的行为，(3)哪些基因会改变它们对新刺激的表达水平。这项工作将为行为和遗传过程如何导致遗传变异提供一个清晰的图景，也将为理解对新奇反应作为一种普遍现象提供一个模型系统。该项目的更广泛影响将包括培养本科生和研究生，并进一步发展孔雀鱼模型系统，使其成为广泛理解进化的一个众所周知的范例。

Behavioral and Genetic Mechanisms for Frequency-Dependent Survival and Mating Advantage in GuppiesIOB-0743990Anne Houde In the genomic era, it has become increasingly obvious that most traits that are relevant to the health, longevity, and fertility of organisms (including humans) are influenced by genetic variation (polymorphism). Despite intense interest in mapping and characterizing the responsible genes, the processes responsible for maintaining genetic variation are generally unknown. One reason is that direct experimental investigations are impossible in humans and difficult and expensive in most model organisms. More tractable species that can be studied in both natural and laboratory settings are needed to address this question. Wild guppies exhibit one of the most striking examples of polymorphism among animals (male color pattern variation), thought to be maintained by mating and survival advantages to rare or uncommon color types. Mating advantage appears result from female sexual responses to unusual males, and survival advantage appears to result from selective predation on common color types. This project will elucidate behavioral and genetic mechanisms underlying these patterns. Studies will examine (1) behavioral mechanisms leading to mating advantage for rare types, (2) behavioral responses of a predatory killifish to rare vs. common types and (3) brain gene expression changes that occur when guppies respond to novel sexual and environmental stimuli. Specific outcomes include determining (1) if female guppies have a specific preference for rare male types, (2) if prior experience with color types affects the predator's behavior and (3) which genes change their levels of expression in response to novel stimuli. This work will provide a clear picture of how behavioral and genetic processes contribute to genetic variation, and will also provide a model system for understanding response to novelty as a general phenomenon. Broader impacts of the project will include training of undergraduate and graduate students and further development of the guppy model system as a well-known exemplar for broad understanding of evolution.