Digestive adaptations for herbivory
Thirty-six years after five breeding pairs of Podarcis sicula (Italian Wall Lizards) were moved from Pod Kopiste to Pod Mrcaru in the Croatian Adriatic, Herrel et al. (2008, PNAS) revealed that the transplanted lizards on Pod Mrcaru had become mostly herbivorous and developed morphological adaptations for consumption of a plant diet, previously thought only to evolved over longer time scales. For my dissertation, I am examining changes in gut function and structure that have arisen to accommodate this dietary shift. In laboratory experiments conducted at the University of Zagreb in Croatia in collaboration with Dr. Zoran Tadic, we are determining the lizards' digestive performance. Additionally, in collaboration with Dr. Anthony Herrel, we are using DNA and RNA analyses to characterize the gut microbial communities of lizards from each population.
This research is funded through a Catalyzing New International Collaborations (CNIC) grant from NSF.
Acquisition and variation of gut microbes in an herbivorous lizard
Herbivory in lizards and requires communities of symbiotic gut microbes and for >30 years, social interactions have been a hypothesized route of microbe transfer. Using Illumina sequencing in collaboration with the Earth Microbiome Project, we characterized the spatial, temporal, and social variation of these vital microbial communities in Green Iguanas (Iguana iguana). Generally, we found high variation in microbial community composition by each factor we investigated, including within recaptured individuals over time. Intergenerational microbial community transmission is unlikely to be as important as previously hypothesized based on the near absence of intergenerational associations and the dissimilarity in microbial community assemblages between hatchlings and adults/subadults. However, within-hatchling microbial admixing was common.
Are you an undergrad interested in this kind of research? Email me or Dr. German to find out how you can get involved!