Collaborative Research: Development and Identity of Sexually Dimorphic Reproductive Signals and Responses by African Elephants

合作研究：RUI--性双态的发展和认同非洲象的生殖信号和反应本着BIO C-Rui计划的精神，这项建议跨越了学科、部门和机构的界限。该项目将回答有关在生物和化学界面上使用创新技术进行生殖交流的最近机制的五个问题。非洲象将被用来测试有性二态生殖信号和反应的发育模式假说。这不仅是因为大象作为研究模型提供了独特的优势，还因为基础科学研究可以提供关于这些具有生态重要性的濒危动物的知识，这可能有助于它们的长期生存。这个研究团队包括一名动物行为学家(舒尔特博士)和一名有机化学家(古德温博士)，他们都在以本科生为主的机构进行过与大象有关的成功研究。拉斯穆森博士加入了这个团队，他描述了亚洲大象排卵前信息素的特征，并在理解大象的生化、行为和嗅觉方面做出了重大贡献。这些科学合作者是教育工作者，他们认为本科生学习科学最好的方式是做科学，即与科学家一起参与研究，在科学会议上展示结果，以及共同撰写手稿。本科生合作者将积极参与这项对性二态生殖信号和反应的研究。一夫多妻制动物经常表现出极端的性别二态，其中雄性和雌性可能生活在非常不同的社会结构中。在哺乳动物中，雌性通常在很少或没有雄性帮助的情况下抚养后代。非洲象(Loxodonta Africana)很好地说明了这种模式。在繁殖季节，两性之间的互动尤其普遍，因为在繁殖季节，个体使用各种交流行为来竞争和选择配偶，以及维持社会联系。化学信号和相关的触觉行为是评价生殖条件和吸引交配的主要手段。化学信号产生和性别特异性反应的发展几乎没有受到关注。事实上，在一项研究中，很少在同一物种中同时比较与生殖有关的性别二态交流模式。这些领域的焦点问题分三组提出：第一组：排卵前尿液中诱导男性生殖行为的特殊化学信号是什么？引发女性更高的社会反应性？第二组：在男性和女性的不同发育过程中，是否存在以下可识别的阶段：A、男性对排卵前尿液及其特殊化学信号的反应(S)？女性对排卵前尿液及其特定化学信号的反应(S)？第三组：基于前两组的结果，男性和女性对已知化学信号源和特定信号化合物以及更广泛地显示与生殖有关的行为的个体发育模式是什么？这些问题首先是通过研究雌性到雄性的信号(IA和IIA)，然后是雌性到雌性的信号(IB和IIB)，最后是通过比较两种发育途径(III)。具体来说，寻找答案是：(I)收集圈养和野生非洲母象的尿液；(Ii)对尿液样本进行行为生物分析，以确定雄性和雌性同种大象的反应；(Iii)对具有生物活性的尿液部分进行化学分析，以确定有机化合物；(Iv)对圈养的非洲象和随后的野生非洲象进行选定的尿液成分生物分析；(Vi)观察野生非洲象的生殖化学联系。拟议的研究将确定生殖行为的最接近的化学原因，并阐明交流的性别二态发育模式。这项研究将为未来基于男性的信号的研究和这一主题的最终问题奠定基础。这些发现可能有助于在实践中保护濒危大象和其他物种。

Collaborative Research: RUI - Development and Identity of Sexually DimorphicReproductive Signals and Responses by African ElephantsIn the spirit of the BIO C-RUI program, this proposal crosses disciplinary, departmental, and institutional boundaries. The project will answer five questions regarding the proximate mechanisms of reproductive communication using innovative techniques at the interface of biology and chemistry. African elephants will be used to test hypotheses on developmental patterns of sexually dimorphic reproductive signals and responses. This is not only for the distinct advantages elephants offer as a research model, but also because basic scientific research can provide knowledge about these ecologically important, endangered animals that may aid in their long-term survival. This research team includes an animal behaviorist (Dr. Schulte) and an organic chemist (Dr. Goodwin), each with a track record of successful elephant-related research at predominantly undergraduate institutions. Dr. Rasmussen, who characterized the pre-ovulatory pheromone in Asian elephants and has made substantial contributions to the understanding of elephant biochemistry, behavior and olfaction, joins the team. These scientific collaborators are educators who believe that undergraduates learn science best by doing science, i.e. by research participation with scientists, presentation of results at scientific meetings, and co-authoring manuscripts. Undergraduate collaborators will actively participate in this research on sexually dimorphic reproductive signals and responses.Polygamous animals often display extreme sexual dimorphism, where males and females may live in very different social structures. In mammals, females typically raise the offspring often with little or no male assistance. African elephants (Loxodonta africana) illustrate this pattern very well. Intersexual interaction is especially prevalent during the breeding season when individuals use a variety of communicative behaviors to compete for and select mates as well as maintain social bonds. Chemical signals and related tactile behaviors are primary means of evaluating reproductive condition and attracting mates. The development of chemical signal production and sex-specific responses has received little attention. In fact, sexually dimorphic communication patterns related to reproduction have rarely been compared within the same species simultaneously in a single study. Focal questions in these arenas are posed in three sets:SET I: What are the specific chemical signals in pre-ovulatory urine that: A. Elicit male reproductive behavior? B. Elicit heightened female social responsiveness?SET II: During the differential development of males and females are there recognizable stages of: A. Male responses toward pre-ovulatory urine and its specific chemical signal(s)? B. Female responses toward pre-ovulatory urine and its specific chemical signal(s)?SET III: Based on the results in the first two sets, what are the comparative ontogenetic patterns of male and female responses toward known chemical signal sources and to specific signal compounds and more generally in the display of reproductively related behaviors? These questions are investigated first by a study of female-to-male signals (IA and IIA), then female-to-female signals (IB and IIB) and finally by comparing the two developmental pathways (III). Specifically, answers are sought by: (i) Collecting urine from captive and wild female African elephants; (ii) Performing behavioral bioassays of urine samples for the responses of both male and female conspecifics; (iii) Chemically analyzing bioactive urine fractions to identify organic compounds; (iv) Bioassaying selected urinary components with captive and then wild African elephants; (vi) Observing wild African elephants for reproductive chemotactile communication.The proposed research will identify proximate chemical causes of reproductive behavior and elucidate sexually dimorphic developmental patterns of communication. This study will lay the groundwork for future investigation on male based signals and of ultimate questions on this topic. The findings may assist in the conservation of endangered elephants in practice and other species.