PROJECT SUMMARY
The marmoset monkey has emerged recently as a highly tractable nonhuman primate model of aging.
Marmosets have relatively short lifespans, and exhibit similar aging-related declines to humans, including
changes in blood pressure, immune function, and cognition. However, there is a biological “black box” in
marmoset biology, the implications of which few researchers mention. Marmosets are natural chimeras, with
siblings exchanging genetic material in utero. Some reports limit chimerism to only hematopoietic tissues (e.g.,
blood, spleen, bone marrow) whereas others suggest that other types of tissue can be chimeric, including
germline tissues, with implications for heritability. It remains unclear how the presence of multiple genomes in
an individual impacts marmoset physiology and the risk of age-related morbidities. The rationale for this study
is that to understand the benefits and limitations of the marmoset model we must characterize the emergence
and impacts of chimerism on an individual. These efforts are imperative to the overall objective of being able to
predict and determine outcomes of chimerism. With the increasing appreciation that chimerism in humans is
both widespread and a major driver of human health, marmoset models of chimerism may be a pivotal tool in
aging research. Therefore, the specific aims for this proposal to 1) Define and map chimerism in marmosets, 2)
Characterize the developmental dynamics of marmoset chimerism, and 3) Evaluate the costs of chimerism for
aging marmosets.