By Jacqueline N. Rubin, WNPRC editorial intern
Sept. 2, 2020
The Wisconsin National Primate Research Center (WNPRC) and the Southwest National Primate Research Center (SNPRC) have received a $4.9 million grant from the National Institutes of Health to double their yield of common marmosets (Callithrix jacchus) for biomedical researchers needing these primates for neuroscience research. While addressing the high demand for these animals in NIH-sponsored research studies, the funding supports the characterization of their genomes to facilitate their development as animal models of human diseases. Additionally, the plan provides assurances for improved and expanded animal care as scientists use the animals more frequently in this area of research.
The principle investigators on this five-year U24 grant titled Collaborative Expansion of Marmoset Colonies for Neuroscience Research, are WNPRC Director Jon Levine, Ph.D., professor of neuroscience at the University of Wisconsin–Madison, Corinna Ross, Ph.D., associate professor of population health at the SNPRC, and Jeffrey Rogers, Ph.D. associate professor of a molecular and human genetics at Baylor College of Medicine. A U24 is classified as a resource-related research project, or also, a cooperative agreement. The awarding NIH agencies include the National Institute of Mental Health (NIMH) and the National Institute of Neurological Disorders and Stroke (NINDS).
The nonhuman primate colony at the WNPRC is composed of approximately 1,119 rhesus macaques, 226 cynomolgus macaques, and 247 common marmosets. The SNPRC nonhuman primate colony consists of nearly 400 marmosets, 850 rhesus macaques and more than 1,000 baboons.
The common marmoset species has emerged as a promising model to help researchers fully comprehend the primate brain, founded on the basis that many marmoset behaviors share similarities with analogous human behaviors. In the past five years, there has been a surge in requests for Callithrix jacchus for biomedical research purposes, even though labs have been studying brain–behavior links with this primate for more than 40 years. According to Nature Methods, marmosets are capable of communicating through a range of postures, facial expressions and vocalizations. Marmosets are known for their cooperative social behavior: they have the ability to communicate by calling to one another in a back-and-forth, conversation-like manner. In addition, they are small in size, provide rapid reproductive maturation, have high fertility rates, consist of social behaviors and communication patterns that mimic those of humans.
Overall, these traits pose practical advantages for neuroscientific studies and are the main reasons behind the recent demand for marmosets, specifically in studies that utilize new embryonic genome editing techniques. Common marmosets have been genetically engineered throughout the years to make their brains easier to image and visualize, according to Science Magazine.
A review on marmoset brain mapping in Neuroscience Research addressed additional research directions: Further exploration of the neuroscience of marmoset colonies aims to map the structure and function of neuronal circuits to ultimately comprehend the immense multifaceted nature of the human cerebrum. According to the National Institute of Mental Health, the relatively small brain size and lissencephalic cortex make the marmoset brain an attractive model for scientists to study. In addition, technology for germ line transmission of exogenous genetic information is now possible through studying the marmoset brain.
Studying marmosets and their behavior is part of a wider effort to further improve neuroscientific studies. At the WNPRC, Jon Levine and David Abbott have studied marmoset sex behavior, metabolism, and serotonergic circuitries controlling mood and affect. Marina Emborg is studying marmoset models for Parkinson’s disease therapies. At the SNPRC, marmoset models are critical in furthering research on aging and metabolic diseases, research on Parkinson’s and neurodegenerative disorders, and infectious disease research.
“This grant demonstrates the willingness of multiple National Primate Centers to work closely with each other to maximize their potential and reach”, said SNPRC Director Deepak Kaushal.
A deeper understanding of the marmoset cerebrum may allow the scientists to understand neurological disorders such as autism and schizophrenia, as well as mental and mood disorders, through, for example, neurotoxin dosing (Eslamboli et al., 2007), direct intracerebral delivery of viral vectors encoding for gene mutations of interest (Kirik, Zinchenko, Shestakov, & Babykin, 2003) or by exposure to specific antibodies.
“We are excited to be a part of this national marmoset colony expansion effort,” Levine added. “This is an initiative that will finally provide sufficient numbers of healthy, fully-genotyped common marmosets to meet the demand by leading neuroscientists conducting leading-edge research.”