Molecular physiology of chemical defenses in a poison frog [RESEARCH ARTICLE]

Stephanie N. Caty, Aurora Alvarez-Buylla, Gary D. Byrd, Charles Vidoudez, Alexandre B. Roland, Elicio E. Tapia, Bogdan Budnik, Sunia A. Trauger, Luis A. Coloma, and Lauren A. O'Connell Poison frogs sequester small molecule lipophilic alkaloids from their diet of leaf litter arthropods for use as chemical defenses against predation. Although the dietary acquisition of chemical defenses in poison frogs is well documented, the physiological mechanisms of alkaloid sequestration has not been investigated. Here, we used RNA sequencing and proteomics to determine how alkaloids impact mRNA or protein abundance in the little devil frog (Oophaga sylvatica), and compared wild-caught chemically defended frogs with laboratory frogs raised on an alkaloid-free diet. To understand how poison frogs move alkaloids from their diet to their skin granular glands, we focused on measuring gene expression in the intestines, skin and liver. Across these tissues, we found many differentially expressed transcripts involved in small molecule transport and metabolism, as well as sodium channels and other ion pumps. We then used proteomic approaches to quantify plasma proteins, where we found several protein abundance differences between wild and laboratory frogs, including the amphibian neurotoxin binding protein saxiphilin. Finally, because many blood proteins are synthesized in the liver, we used thermal proteome profiling as an untargeted screen for soluble proteins that bind the alkaloid decahydroqu...
Source: Journal of Experimental Biology - Category: Biology Authors: Tags: RESEARCH ARTICLE Source Type: research