RUI:OSIB:The effects of high disease risk on uninfected animals

Chapman University, Orange CA

Investigators

Abstract

Pathogens, such as harmful bacteria and viruses, can cause significant damage once they infect an organism. As such, organisms have evolved physiological strategies to deal with infections (i.e., to destroy pathogens or reduce their damage). Interestingly, research has shown that in many species, including in humans, the mere risk of infection (such as observing someone who is sick) can already trigger physiological responses. However, these physiological responses to disease risk are not well characterized. In particular, it is not known if these physiological responses to disease risk affect survival and reproduction. To address those gaps in knowledge, the proposed work will use a model species and a parasite that infects that species and causes visible symptoms. An understanding of the mechanisms driving physiological response to disease risk will advance human health, animal welfare, as well as likely affect the way biomedical research is conducted. Undergraduate students from backgrounds historically underrepresented in science will participate in the research, providing a formative educational experience. Undergraduates will also be matched with high school students from similar backgrounds to facilitate a peer mentoring program that will increase student interest in science, as well as improve their confidence in their ability to pursue their own careers in science. Middle school students who visit the university during the university’s open day will have the chance to interact with the older groups of students and learn about their experiences. Emerging research is suggesting that pathogens affect not only infected animals, but also those around them. For example, recent studies have shown that cohabitation with sick conspecifics or exposure to disease or parasite cues leads to changes in the physiology and behavior of healthy conspecifics. If these physiological changes help reduce disease burden or speed up recovery from disease, they can have cascading effects on disease dynamics. The objective for this proposal is to study how exposure to disease risk affects the physiology and reproductive investment of uninfected animals, as well as their own responses upon infection. To accomplish this goal, a host-parasite system (canary - Mycoplasma gallisepticum) will be used, where responses to disease risk have already been demonstrated to occur. To quantify how observation of infected symptomatic birds (disease risk treatment) relative to observation of healthy birds affects animals, the project will 1) use a transcriptomic approach to address how multiple organs respond to disease risk over time, 2) evaluate whether and how disease risk information modifies the damage and the time course imposed by a subsequent infection, and 3) quantify changes in reproductive behavior and investment imposed by the presence of disease risk. Integrated into this project are several research and engagement opportunities for under-represented middle, high school, and undergraduate students interested in STEM. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.