We are excited to announce that we have recently received two NSF grants to fund our projects on population genomics of North American rattlesnakes and functional genomics of regenerative organ growth in vertebrates!

NSF-DEB: Systematics, introgression, and adaptation in Western Rattlesnakes: a model system for studying gene flow, selection, and speciation. Todd Castoe as PI, and Stephen P. Mackessy (U. Northern Colorado), Jesse Meik (Tarleton State U.) and Matthew Fujita (UTA) as Co-PIs. 

The overarching goals of this research program are to understand the interaction of admixture and selection in speciation, and to leverage an empirical system to test how these processes may influence coalescent-based species delimitation methods. This research program will focus on the Western Rattlesnake species group (Crotalus viridis species complex and its sister taxon, C. scutulatus; collectively Cvos hereafter) as a study system. This recently diverged species complex has offered major challenges for systematics, yet provides an ideal model system for studying speciation and species delimitation. This integrated study will combine genomic and phenotypic data to delimit species, inform species delimitation approaches, and provide new genome-scale insight into the process of speciation. This research program will also test hypotheses about the repeatability of patterns selection in the processes of speciation and resistance to gene flow and hybridization.

NSF-IOS: Collaborative Research: Integrated mechanisms underlying the regulation of Intestinal form and function. Todd Castoe and Stephen Secor (U. Alabama) as PIs, Saiful Chowdhury (UTA-Chemistry and Biochemistry) as Co-PI.

Vertebrates possess the physiological capacities to alter intestinal performance that are adaptively linked to their feeding habits. For example, species that naturally experience long episodes of fasting between large meals (e.g., sit-and-wait foraging snakes) experience rapid upregulation of intestinal form and function with feeding, and subsequent intestinal atrophy and downregulation following digestion. In contrast, frequently feeding species (e.g., active-foraging snakes) experience only modest change in intestinal form and function with each meal. Currently unknown are the cellular and molecular mechanisms that underlie the structural and functional flexibility of the intestine, and whether such mechanisms are shared across vertebrates that widely or narrowly regulate intestinal performance. By leveraging the extreme range in intestinal responses exhibited by snakes and other vertebrates, and recently available genomic resources, this research program will identify the underlying mechanisms of intestinal flexibility and test whether these mechanisms are shared across lineages and regulatory phenotypes.

Additional details on both projects can be found on our Funding page.