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

合作研究：非洲象性别二态性生殖信号和反应的发展和识别

• 批准号: 0217068
• 负责人: Thomas Goodwin
• 金额: --
• 依托单位: Hendrix College
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-09-15 至 2008-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0217068&HistoricalAwards=false
• 关键词: Collaborative; Research; Development; Identity; Sexually

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.

合作研究：RUI -非洲象的性二态生殖信号和反应的发展和身份本着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。该项目将回答五个问题，关于生殖沟通的近机制，使用创新技术在生物学和化学的接口。 非洲象将被用来测试性二态生殖信号和反应的发育模式的假设。这不仅是因为大象作为研究模型的独特优势，而且还因为基础科研可以提供有关这些具有重要生态意义的濒危动物的知识，这些知识可能有助于它们的长期生存。该研究团队包括一名动物行为学家（Schulte博士）和一名有机化学家（Goodwin博士），他们都在主要的本科院校进行了成功的大象相关研究。 Rasmussen博士加入了该团队，他描述了亚洲象排卵前信息素的特征，并对大象生物化学，行为和嗅觉的理解做出了重大贡献。这些科学合作者是教育工作者，他们认为本科生最好通过做科学来学习科学，即通过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。本科合作者将积极参与这项关于性二态生殖信号和反应的研究。一夫多妻动物通常表现出极端的性二态性，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。 两性间的互动在繁殖季节尤其普遍，此时个体使用各种交流行为来竞争和选择配偶以及维持社会关系。化学信号和相关的触觉行为是评估生殖状况和吸引配偶的主要手段。化学信号产生和性别特异性反应的发展很少受到关注。事实上，与生殖有关的两性沟通模式很少在同一物种中同时进行比较。 这些领域的焦点问题分为三组：第一组：排卵前尿液中的特定化学信号是什么？诱导男性生殖行为？ B。激发女性的社会反应？第二组：在男性和女性的不同发展过程中，有以下几个可识别的阶段：A。男性对排卵前尿液及其特定化学信号的反应？ B。女性对排卵前尿液及其特定化学信号的反应？第三组：根据前两组的结果，男性和女性对已知化学信号源和特定信号化合物的反应以及更普遍的生殖相关行为的表现的比较个体发育模式是什么？这些问题首先通过研究女性对男性的信号（IA和IIA），然后女性对女性的信号（IB和IIB），最后通过比较两种发展途径（III）进行研究。具体而言，通过以下方式寻求答案：㈠收集圈养和野生雌性非洲象的尿液; ㈡对尿液样本进行行为生物测定，以了解雄性和雌性同种的反应; ㈢对尿液中的生物活性成分进行化学分析，以确定有机化合物; ㈣对圈养和野生非洲象的选定尿液成分进行生物测定;（vi）观察野生非洲象的生殖化学触觉交流：拟议的研究将确定生殖行为的近因化学原因，并阐明两性发育的交流模式。本研究将为进一步研究基于男性的信号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。