This January we introduced you to Amanda Lea. She was awarded a Leakey Foundation research grant in our fall 2014 cycle for her project entitled “Effects of social conditions on DNA methylation and immune function.” Here she updates us on the her latest field season.
When we dart a baboon, we process it near its social group so that the animal can be released quickly and efficiently once it recovers from the anesthetic. We take the collected samples back to our permanent tent camp on the edge of Amboseli National Park. There, I work to further process all blood and tissue for temporary storage and eventual export to the United States. Here is a picture of me, happily processing samples, in our makeshift tent ‘laboratory’. Photo credit: Jenny Tung
I was recently funded by the Leakey Foundation to investigate how social conditions influence gene regulation in wild baboons. Many primate species, including humans, live in complex social environments, and research across primate species has demonstrated a robust link between poor quality social conditions (e.g., social isolation or low social status) and compromised health. Thus, it appears that social experiences can profoundly shape fitness-related traits in primates; however, our understanding how this occurs at the molecular level is extremely incomplete. To address this gap, my project tests the hypothesis that social adversity influences health-related traits by altering the way genes are expressed. To do so, I am combining behavioral data from a well-studied population of yellow baboons with genome-wide profiles of DNA methylation (an epigenetic gene regulatory mechanism) and gene expression levels.
An important component of the baboon social environment is grooming, shown here, which is a primary mechanism for forming and maintaining social relationships.
I recently returned from my third field season in Amboseli, where I was working to collect blood samples from baboons for my genomic work. The baboons that I study are part of a long-term project headed by Jeanne Altmann, Susan Alberts, Beth Archie, and Jenny Tung. The project is known as ‘The Amboseli Baboon Project’ (ABRP), and has been ongoing for over four decades. Animals in the study population are regularly monitored by a highly skilled team of field observers and are occasionally darted to collect blood samples for genetic and genomic analyses. The ABRP has been darting animals for many years using a conservative darting protocol that is aimed at maximizing safety and preserving the habituation of the study animals. Animals are generally darted very early in the morning, using a hand held blow gun carrying an anesthetic-bearing dart. Once the animal is anesthetized, it is quickly moved away from its social group to a nearby processing area. There, we work quickly to collect blood and tissue samples, morphological measurements, and information about tooth wear. Following this effort, the sedated animal is allowed to regain consciousness in a covered holding cage, and is then released near its social group upon recovery and closely monitored. This entire process can take quite some time, and requires extensive preparation. Most importantly, a successful darting and sample collection effort relies on the participation and expertise of many skilled researchers and field assistants.
We take a long list of laboratory supplies into the field with us on darting days. These supplies are for drawing and processing blood and tissue, taking morphological measurements, and documenting tooth wear patterns in each animal we dart.
I was able to participate in this darting effort over the course of the summer (thanks to funding from the Leakey Foundation), and successfully collected blood from twenty baboons during my field season. Importantly, all of the individuals I collected samples from were born in the study population and have been monitored by the ABRP for their entire life. Therefore, I can link my genomic data with extremely fine-grained information about the social conditions each individual has experienced, from birth through adulthood. I plan to return next summer for another field season and look forward to collecting another set of samples and spending more time with the baboons. For now, I am busy extracting DNA and RNA from the samples I collected this year and preparing them for high-throughput sequencing (to measure genome-wide DNA methylation and gene expression levels).