DISSERTATION RESEARCH: Proximate Mechanisms of Aggression in Role Reversed Species

杂交是两个不同物种的繁殖，当杂交种相当健康时，有可能将两个物种合并为一个，或者当杂交种表现不佳时，保持物种分离。在巴拿马西部，被称为北方蓝花楹和垂翅蓝花楹的热带滨鸟的物种范围相遇，它们形成了一个杂交区。Jacanas表现出交配角色逆转，女性控制访问配偶的竞争领域，包括男性的后宫，男性提供所有的父母照顾。具有这种独特交配系统的物种之间杂交的不寻常情况提供了一个窗口，从雌性的角度研究物种特异性交配边界失败的原因和方式。遗传和实验证据表明，物种之间攻击行为的差异可以解释杂交模式。 较具攻击性的物种的雌性产生大多数杂交后代。这项拟议中的研究采用了评估基因表达的技术，以检查杂交物种之间攻击行为的变化。这项研究解决了生态学、进化和行为学中的一个基本问题，即行为差异的遗传基础是什么？这可以1）提高我们对物种形成中重要的行为机制的理解，2）提供对雄性和雌性之间行为差异的遗传机制的洞察。 在巴拿马的野外，通过与当地学龄儿童和生态旅游者的研讨会，将对科学和研究的理解进行交流。在最近分化的物种之间，交配行为可以阻碍或促进生殖隔离。理论和经验证据表明，女性择偶和男性竞争，但很少有人知道的相对作用。直到最近，女性的攻击性才被认为是一种适应性行为，其潜在机制与男性的机制相比还没有得到很好的理解。理解女性竞争表型的进化意义的关键一步是确定其潜在的基因组机制。拟议的研究的目标是阐明女性竞争表型的分子基础，通过识别候选基因簇，其差异表达是负责一致的侵略行为的变化。本研究结合了侵略检测与转录组学的方法来解决这个问题的角色逆转，杂交北方Jacanas（Jacana spinosa）和垂悬Jacanas（J. jacana）在中美洲。这个项目是新的理解机制，表型变化的角色逆转物种分歧，这可以促进我们的理解生物体如何响应和适应不断变化的环境选择。通过确定潜在的侵略基因是如何在角色颠倒的女性和男性之间差异表达的，拟议的研究将扩展在性选择理论中的一般原则，这些原则已经在众所周知的男性主导的系统中发展起来。此外，该项目还研究了野生、自由生活、非模式生物中复杂行为特征的遗传基础，这对于理解自然条件下生态相关表型的进化至关重要。

Hybridization, the breeding of two separate and distinct species, has the potential to merge two species into one when hybrids are fairly healthy, or keep the species separate when hybrids fare poorly. In western Panama, where the species ranges of the tropical shorebirds known as Northern Jacanas and Wattled Jacanas meet, they form a hybrid zone. Jacanas exhibit mating role reversal where females control access to mates by competing for territories encompassing a harem of males, and males provide all parental care. The unusual circumstance of hybridization between species with such a unique mating system offers a window into examining why and how species-specific boundaries to mating fail, from a female perspective. Genetic and experimental evidence suggests that differences in aggressive behavior between the species may explain patterns of hybridization. Females of the more aggressive species produce the majority of hybrid offspring. The proposed research employs techniques to assess the expression of genes to examine variation in aggressive behavior between the hybridizing species. This research addresses a fundamental question in ecology, evolution, and behavior what is the genetic basis of behavioral differences? This can 1) improve our understanding of the behavioral mechanisms important in species formation, and 2) provide insight into the genetic mechanisms underlying behavioral differences between males and females. Understanding of science and research will be communicated through workshops with local school aged children and ecotourists at the Panamanian field site.Between recently diverged species, mating behavior can either impede or promote reproductive isolation. Theoretical and empirical evidence demonstrates this for female mate choice and male competition, but little is known about the relative roles of each. Female aggression has only recently been recognized as an adaptive behavior, and how its underlying mechanisms compare to those of males is not well understood. A key step towards understanding the evolutionary significance of the competitive phenotype in females is determining its underlying genomic mechanisms. The goal of the proposed research is to elucidate the molecular basis of the female competitive phenotype by identifying clusters of candidate genes whose differential expression is responsible for consistent variation in aggressive behavior. This study combines aggression assays with a transcriptomic approach to address this question in role reversed, hybridizing Northern Jacanas (Jacana spinosa)and Wattled Jacanas (J. jacana) in Central America. This project is novel with respect to understanding the mechanisms by which phenotypes change as role reversed species diverge, which could advance our understanding of how organisms respond and adapt to changing environmental selection. By identifying how the genes underlying aggression are differentially expressed between role reversed females and males, the proposed research will expand upon general principles in sexual selection theory that have been developed in well-known male-dominant systems. Furthermore, this project investigates the genetic underpinnings of complex behavioral traits in wild, free-living, non-model organisms, which is vital for understanding the evolution of ecologically relevant phenotypes under natural conditions.