Doctoral Dissertation Improvement: C-peptide of Insulin as an Index of Energy Expenditure in Wild Chimpanzees

研究人员将在乌干达的Kibale国家公园对黑猩猩进行观察，以验证一个假设，即成年雄性的尿c肽（UCP）水平的每日变化与食物摄入量和攻击性等消耗能量的行为有关。c肽分子是胰岛素合成的副产物，当它从尿液中排出时，可以准确地指示胰岛素的产生。胰岛素刺激血液中葡萄糖的吸收，从而反映机体能量的可用性。这项研究将首次直接评估c肽作为野生灵长类动物能量平衡指标的有效性。以前的评估都是间接的，因为他们使用的是每月平均饮食质量，而不是每天监测个人行为。这项研究的目的是解释为什么据报道，占主导地位的雄性黑猩猩的UCP水平低于其下属，尽管UCP水平与能量摄入有关，当水果供应充足时，UCP水平会更高。这项研究的智力价值在于它的发现可能对现场条件下能量学研究的方法论发展产生影响。灵长类动物能量状态的非侵入性指标一直是难以捉摸的。c肽有望作为能量平衡、能量摄入或能量消耗的指标，本研究将评估其价值。了解雄性黑猩猩的能量消耗与其统治地位之间的关系，也将揭示迄今为止被忽视的群居哺乳动物统治地位的能量成本。该项目的更广泛影响包括对马凯雷雷大学生物野外站运作的贡献。教育项目将在当地学校开展，以提高人们对野生动物的认识和兴趣。该博士论文研究项目将有助于研究生的学术培训，其结果将在同行评审的期刊上发表。

Chimpanzees will be observed in Kibale National Park, Uganda, to test the hypothesis that daily variation in urinary C-peptide (UCP) levels among adult males is correlated with both food intake and energetically expensive behaviors, such as aggression. The C-peptide molecule is a by-product of insulin synthesis and when excreted in the urine gives an accurate indication of insulin production. Insulin stimulates the uptake of glucose from the bloodstream and thus reflects the availability of energy for the organism.This study will provide the first direct assessment of the effectiveness of C-peptide, as an index of energy balance in wild primates. Previous assessments have been indirect since they used monthly averages of dietary quality, rather than daily monitoring of individual behavior. This research is designed to explain why dominant male chimpanzees have been reported to have lower UCP levels than subordinates, even though UCP levels track energy intake, being higher when and where fruit availability is greater.The intellectual merit of this study lies in the possible implications its findings will have for the methodological development of energetics research in field conditions. Non-invasive indices of the energetic condition of primates have always been elusive. C-peptide is promising as an indicator of energetic balance, energy intake, or energy expenditure and this study will assess its value. Understanding the relationship between energy expenditure in male chimpanzees and their dominance rank will also reveal hitherto overlooked energetic costs of dominance in social mammals.The broader impacts of the project include the contribution to the functioning of Makerere University Biological Field Station. Educational programs will be carried out in local schools to raise awareness and interest in wildlife. This doctoral dissertation research project will contribute to the academic training of a graduate student and the results will be published in peer-reviewed journals.