Collaborative Research: Balancing selection and MHC variation in an endangered bird

保护生物学中的一个主要问题是，为什么一些遗传变异水平较低的种群保持相对稳定，而另一些种群的规模却在下降。稳定的种群可能没有丢失与抗病相关的遗传变异，例如被称为主要组织相容性复合体(MHC)的一套抗病基因。理论表明，自然选择更有可能在经历过大小下降的种群中保持重要的MHC变异。这项研究将使用大草原鸡历史和当代种群的数据，直接估计MHC和其他免疫基因的自然选择。大草原鸡是北美最受威胁的鸟类之一。该项目还将研究MHC基因变异与两个小种群中寄生虫、免疫和存活率之间的关联，这两个小种群正在通过易位(威斯康星州)和圈养繁殖(德克萨斯州)进行增强以增加遗传变异。这项研究的结果将对生物学家研究种群规模对疾病和寄生虫抵抗力的影响具有价值，并将为圈养繁殖和转移动物提供管理指南，随着草原栖息地的持续丧失，这些做法可能会增加。研究生和博士后研究员将接受免疫遗传学方面的培训，该项目应该会为研究其他物种的免疫相关基因带来有价值的新遗传标记。PI将与密尔沃基和达拉斯-沃斯堡的环境教育中心合作，开展关注野生动物健康的公民科学和教师教育项目。结果将广泛传播给州和联邦野生动物机构、环境组织和普通公众。

A major question in conservation biology is why some populations with low levels of genetic variation remain relatively stable while others decline in size. Stable populations may not have lost genetic variation related to disease resistance, such as the suite of resistance genes known as the Major Histocompatibility Complex (MHC). Theory suggests that natural selection is more likely to maintain functionally important MHC variation in populations that have experienced declines in size. This study will make direct estimates of natural selection on the MHC and other immunity genes using data from both historic and contemporary populations of the greater prairie-chicken, which is one of the most threatened species of bird in North America. This project will also examine the association between variation at MHC genes and parasites, immunity and survival in two small populations that are undergoing augmentation with translocations (Wisconsin) and captive breeding (Texas) to increase genetic variation. The results of this study will be valuable for biologists studying the effects of population size on disease and parasite resistance, and it will provide management guidelines for captive breeding and translocating animals, practices that are likely to increase with continuing loss of prairie habitat. Graduate students and a post-doctoral researcher will be trained in immunogenetics, and the project should lead to valuable new genetic markers for studying immunity-related genes in other species. The PIs will work with environmental education centers in Milwaukee and Dallas-Fort Worth on citizen science and teacher education projects that focus on the health of wildlife. The results will be broadly disseminated to state and federal wildlife agencies, environmental groups and the general public.