Corinna N. Ross, Ph.D.Instructor/Research
University of Nebraska, Lincoln, 2005
I have worked with marmosets, small New World primates since 1995. I received my PhD from the University of Nebraska in 2005 where I had examined the presence and distribution of naturally occurring chimerism between fraternal twins. I stayed for a year of postdoctoral work to continue examining the impact of chimerism on infant care. I became interested in the development of the marmoset as a small primate model for human disease, and moved to San Antonio as a postdoc in 2006.
The focus of my research as a Postdoctoral Fellow at the Barshop Institute for Longevity and Aging has been to develop small nonhuman primate models for aging and healthspan studies. My research has consisted of two major components: (1) pre-and postnatal factors determining the development of obesity and the pathology that follows, including insulin resistance, inflammation and cardiovascular dysfunction (2) the development of marmosets as a model of frailty and functional decline.
Marmosets are small New World primates that offer many advantages over current rodent and nonhuman primate models for translational biomedical research. As primates they share a closer evolutionary history with humans than do rodents.
Marmosets have the shortest average lifespan and fastest reproduction of any anthropoid primate. Additionally, a long history of studies of marmoset hormonal development, reproduction, cooperative breeding behavior, and use as a biomedical model has resulted in a large base of average values for infant growth, body weight, and hematological measures.
Primate models of aging, obesity and frailty. Developmental programming.
Below, I describe my work in these areas to date and my plans for future research.
(1) Development of obesity and its sequelae: Of particular interest to translational research is the potential impact of fetal programming on adult health, aging and healthspan. One of the current projects is to examine whether offspring of mothers identified with the propensity for obesity have increased occurrence of glucose regulatory disorders, and or obesity themselves. Females that are found to be spontaneously obese, those that have diet induced obesity, as well as control females are being characterized for pre-pregnancy behavior and metabolism, placental function and fetal growth, offspring pre and post weaning growth, and offspring behavior and metabolism. We have found that early in development marmoset infants split along two growth trajectories. A faster growth curve results in higher weight at three and six months of age that is associated with increased fat mass rather than increased lean mass.
(2) Modeling frailty and functional decline. Frailty has loosely been defined by researchers as an increasing vulnerability to physiologic stressors and physical decline which leads to death. Studies of frailty in humans have often focused on a core group of characters in order to define frailty, including grip strength, walking speed, weight loss, energy expenditure, and self reports of exhaustion. We recently received two grants to support pilot work towards the development of the marmoset as a model for frailty and functional decline. We are currently developing a number of assessments in these primates including behavioral strength testing to examine muscular decline with age, activity monitoring, measurements of fat and lean mass, and circulating cytokine analysis.
The ability to examine molecular, hormonal, and inflammatory pathways in concert with whole organism phenotyping makes the marmoset models for studies of obesity and frailty unique. Ultimately I envision these two lines of research coalescing thru the examination of epigenetic, genotypic, and phenotypic variation to determine the influence of developmental programming. Understanding the mechanisms underlying the propensity for the development of obesity and frailty will provide critical knowledge needed to prevent and treat these two conditions.
Quantitative Magnetic Resonance Imaging (for body composition assessment)
Computerized Behavioral Data Collection (ObserverTM)
EIA - hormone assays
Ross CN, French JA. (2011) Female marmosets' behavioral and hormonal responses to unfamiliar intrudersAm J Primatol. 2011 Oct;73(10):1072-81.
Tardif SD, Mansfield KG, Ratnam R, Ross CN, Ziegler TE. (2011) The marmoset as a model of aging and age-related diseases.ILAR J. 2011 Feb 8;52(1):54-65.
Tardif SD, Power ML, Ross CN, Rutherford JN, Layne-Colon DG, Paulik MA. (2009) Characterization of obese phenotypes in a small nonhuman primate, the common marmoset (Callithrix jacchus).Obesity (Silver Spring). 2009 Aug;17(8):1499-505.
Ross CN, French JA, Ortí G. (2007) Germ-line chimerism and paternal care in marmosets (Callithrix kuhlii)Proc Natl Acad Sci U S A. 2007 Apr 10;104(15):6278-82.
Ross CN, French JA, Patera KJ. (2004) Intensity of aggressive interactions modulates testosterone in male marmosets.Physiol Behav. 2004 Dec 15;83(3):437-45.