DISSERTATION RESEARCH: Immune-based Maternal Effects: Investigating Variation and Plasticity in Female Deposition of Protective Immune Compounds into Eggs

为了保护雏鸟免受环境中细菌的威胁，鸟类可以做的一件事是将保护性免疫化合物（如抗体）直接转移到它们的蛋中。虽然这些抗体与后代生长和免疫力的提高有关，但尚不清楚卵子抗体水平如何受到疾病风险的影响。这个项目的目的是测试树燕（Tachycineta bicolor）在巢穴中遇到更多细菌的假设，它们的卵中的抗体水平会更高。为了解决这个问题，将使用dna测序来表征燕窝中的细菌群落，并将其与从同一巢中收集的鸡蛋中的抗体水平进行比较。该数据集来自北美各地，将是迄今为止收集到的与任何鸟类有关的细菌群落最全面的数据集。研究人员预测，与植物和动物一样，细菌多样性将在最南的地点（如弗吉尼亚州）最高，在最北的地点（如阿拉斯加）最低。因此，南方鸟类的蛋中应该比北方鸟类含有更多的抗体。除了探索细菌生物地理学的新领域外，这项研究还将为雌鸟保护后代的各种方式带来新的视角。这项研究的结果也将有助于研究人员通过nsf资助的Golondrinas de las Americas网络，对栖息在燕子巢穴、羽毛、粪便、血液和组织中的病原体进行量化的大型合作研究。序列数据将增加通过GenBank公开的16S rRNA基因序列的财富。该项目还将有助于培训在现场和实验室工作的本科生。通过这项研究，学生将有机会与整个西半球的研究人员分享数据、想法和个人互动。

One thing birds can do to protect their young from the threat of bacteria in the environment is to transfer protective immune compounds, such as antibodies, directly into their eggs. Although these antibodies are associated with improved offspring growth and immunity, it is not known how levels of egg antibodies are influenced by disease risk. The purpose of this project is to test the hypothesis that tree swallows (Tachycineta bicolor) encountering more bacteria in their nests will have higher levels of antibodies in their eggs. To tackle this question, bacterial communities in swallow nests will be characterized using DNA-sequencing and compared with antibody levels in eggs collected from the same nests. This data set, from across North America, will be the most comprehensive ever collected on bacterial communities associated with any bird species, and the investigators predict that, as in plants and animals, bacterial diversity will be highest at the most southerly sites (e.g., Virginia) and lowest at the most northerly sites (e.g., Alaska). As a consequence, southern birds should have more antibodies in their eggs than northern birds. In addition to exploring new ground in bacterial biogeography, this study will bring new perspective to the variety of ways in which female birds can protect their offspring. Results from this study will also contribute to a large collaborative study of investigators working to quantify pathogens inhabiting the nests, feathers, feces, blood, and tissues of swallows through the NSF-funded Golondrinas de las Americas network. And sequence data will add to a growing wealth of 16S rRNA gene sequences publically available through GenBank. This project will also contribute to the training of undergraduates working in the field and laboratory. Through this research, students will have the opportunity to share data, ideas, and personal interactions with investigators throughout the hemisphere.