Non-technical abstract Among egg-laying animals, parental care is often important to egg survival. For instance, egg-tending behaviors can reduce growth of pathogens on eggshells and thereby reduce egg mortality. However, many egg-layers lack parental care and instead leave eggs unattended and exposed to environmental pathogens. The PIs are interested in how such animals prevent egg loss in the absence of parental care, and propose a novel source of protection, protective microbes that passively transfer from the reproductive system of the mother to eggshell surfaces during egg-laying. A collaborative team centering on behavioral ecology and microbiology will examine maternal and eggshell microbiome and their interactions with soil pathogens utilizing lizards as a model system to test the hypothesis that the microbiome affects reproductive success, signaling, and behavioral interactions of lizards. The PIs will mentor undergraduate and high school students in research, especially women and STEM underrepresented minorities. They will provide high-quality interdisciplinary training to the next generation of scientists by involving students in all aspects of their research and by translating their work into class-based projects. The proposed research has the potential to shed light on the role of the microbiome on animal behavior.
The interdisciplinary research group will investigate the novel hypothesis that vertically-transmitted cloacal microbes function in egg protection. Preliminary data from Sceloporus virgatus (a phrynosomatid lizard with no parental care) suggest that mature eggs have more bacteria, less fungal growth, and higher hatch success when oviposited than when surgically removed without cloacal contact. The team will: 1) quantify temporal variation in cloacal microbiomes of S. virgatus to test whether females? microbiota change in preparation for egg-laying; 2) use both experiments and observational study to characterize vertical transmission and the role of transmitted microbes in reducing egg infections; 3) relate cloacal microbiota to female reproductive success and signals/cues of reproductive value; and 4) conduct comparative studies across Sceloporus spp. to examine the relationship of reproductive mode (oviparous vs. viviparous) and infection risk on antifungal capacity of cloacal microbiota. Vertical transmission during oviposition is expected to be a general phenomenon, so results should be broadly applicable to other oviparous taxa. The proposed work includes training in sequencing and bioinformatics for the PI, who is based at an undergraduate-serving institution. These methods will be implemented, along with culture-based techniques, in vitro analyses, and field study, in collaboration with carefully mentored undergraduate and high school students. The research will be foundational to the integration of microbiology and behavioral ecology, contributing to long-standing theoretical questions about costs and benefits of parental care (or lack thereof) and sexual signaling, expanding knowledge of microbial diversity and composition in an understudied host lineage, and potentially identifying new antifungal agents.
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.
