DISSERTATION RESEARCH: Neurogenetic Framework of Condition-dependent Mate Choice

进化生物学家的一个主要目标是确定亲缘关系密切的物种如何避免杂交。这通常是行为差异的结果，比如当两个物种的雌性对特定伴侣的偏好不同时。这些偏好对环境的变化非常敏感。本研究的目的是发现不同的环境因素如何影响剑尾鱼的雌性偏好。这项研究是首次尝试评估环境如何影响感官知觉和交配行为的分子基础。此外，这项研究将阐明环境条件如何促进杂交，从而影响物种如何分裂和聚集。在整个研究过程中，研究人员将训练德州农工大学的本科生以及来自墨西哥Calnali的当地学生。这些学生将帮助进行实验，从而获得第一手的研究经验，成为全面发展的科学家。这种训练将增加人们对生态学和进化生物学的兴趣，就Calnali而言，将在一个很少有科学家的地区培养模范科学家。具体来说，研究人员将使用剑尾鱼xiphohorus birchmanni来确定大脑和感觉组织中的哪些基因对雌性饮食和社会环境的变化敏感，以及这些环境因素如何影响雌性对同一物种雄性的偏好。新生剑尾鱼将接受三种社会处理（同种成年、异种成年马林奇剑尾鱼，或不接触成年剑尾鱼）中的一种，以及两种饮食处理中的一种，蛋白质含量不同，这已被证明会影响雌性剑尾鱼的偏好强度。成熟后，雌性对同种与异种雄性气味的偏好将使用二分类交配选择试验进行评估。然后将解剖女性大脑和嗅上皮，并进行RNA-Seq分析以量化基因表达。然后，研究人员将对从RNA-Seq中发现的候选基因进行原位杂交，以确定这些基因的表达位置，从而确定哪些大脑区域与女性择偶有关。组织样本和提取的RNA将被保存在德克萨斯农工大学生物多样性研究和教学馆藏中。整个标本将被加入墨西哥国立自治大学鱼类学收藏。收集的数据将备份到两个工作站和一个专用的外部驱动器上。与录用稿件相关的数据将在适当的电子存储库中存档。

A major goal of evolutionary biologists is to determine how closely related species keep from interbreeding. This is often a result of differences in behavior, such as when females of two species differ in their preferences for particular mates. These preferences can be highly sensitive to changes in the environment. The aim of this study is to discover how female preferences in swordtail fish are affected by different environmental factors. This study is among the first to attempt to assess how the environment affects the molecular basis of sensory perception and mating behavior. Furthermore, this study will shed light on how environmental conditions can promote interbreeding and therefore affect how species split apart and come together. Throughout the course of this study, the researchers will train undergraduate students at Texas A&M as well as local students from Calnali, Mexico. These students will help in conducting experiments, thereby receiving a firsthand experience with research and becoming well-rounded scientists. This training will increase interest in ecology an evolutionary biology and, in the case of Calnali, will create exemplary scientists in a region where there are few.Specifically, the researchers will use the swordtail fish Xiphophorus birchmanni to determine which genes in the brain and sensory tissue are sensitive to changes in female diet and her social environment, and how these environmental factors affect female preference for males of the same species. Newborn swordtails will be submitted to one of three social treatments (raised with adult conspecifics, adult heterospecific Xiphophorus malinche, or no adult exposure) and one of two diet treatments, varying in protein content, which has been shown to affect the strength of female swordtail preference. Upon maturation, female preference for conspecific versus heterospecific male odors will be assessed using a dichotomous mate choice assay. Female brains and olfactory epithelia will then be dissected and undergo RNA-Seq analyses to quantify gene expression. The researchers will then use in situ hybridization on candidate genes found from RNA-Seq to identify where these genes are expressed and therefore what brain regions are implicated in female mate choice. Tissue samples and extracted RNA will be archived in the Texas A&M University Biodiversity Research and Teaching Collections. Whole specimens will be accessioned to the Ichthyology collection of UNAM, Mexico. Data collected will be backed up on two workstations and a dedicated external drive. Data associated with accepted manuscripts will be archived in appropriate electronic repositories.