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血缘关系密切的物种在多大程度上避免杂交。这通常是行为差异的结果，例如当两个物种的雌性对特定配偶的偏好不同时。这些首选项可能对环境的变化高度敏感。这项研究的目的是发现不同环境因素对剑尾鱼雌性偏好的影响。这项研究是第一批试图评估环境如何影响感觉和交配行为的分子基础的研究之一。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。在这项研究的整个过程中，研究人员将培训德克萨斯农工大学的本科生以及来自墨西哥卡尔纳利的当地学生。这些学生将帮助进行实验，从而获得研究的第一手经验，并成为全面发展的科学家。这种训练将提高人们对生态学和进化生物学的兴趣，对于Calnali来说，将在一个极少出现的地区培养出模范科学家。具体地说，研究人员将使用剑尾鱼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。新生的剑尾将被提交给三种社会处理之一(用成年同种、成年异种剑尾鱼饲养，或不接触成年剑尾)，以及两种蛋白质含量不同的饮食处理之一，这已被证明影响雌性剑尾偏好的强度。在成熟后，雌性对同种和异种雄性气味的偏好将使用二分性配偶选择试验进行评估。然后，女性大脑和嗅觉上皮细胞将被解剖，并接受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，以确定这些基因在哪里表达，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将被存档在德克萨斯农工大学生物多样性研究和教学收藏中。整个标本将被纳入墨西哥UNAM的鱼类学收藏。收集的数据将在两个工作站和一个专用外部驱动器上进行备份。与被接受的手稿有关的数据将保存在适当的电子储存库中。

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.