Transcriptomic analysis reveals potential candidate pathways and genes involved in toxin biosynthesis in true toads

Synthesized chemical defenses have broadly evolved across countless taxa and are important in 30 shaping evolutionary and ecological interactions within ecosystems. However, the underlying 31 genomic mechanisms by which these organisms synthesize and utilize their toxins are relatively 32 unknown. Herein, we use comparative transcriptomics to uncover potential toxin synthesizing 33 genes and pathways, as well as interspecific patterns of toxin synthesizing genes across ten 34 species of North American true toads (Bufonidae). Upon assembly and annotation of the ten 35 transcriptomes, we explored patterns of relative gene expression and possible protein-protein 36 interactions across the species to determine what genes and/or pathways may be responsible for 37 toxin synthesis. We also tested our transcriptome dataset for signatures of positive selection to 38 reveal how selection may be acting upon potential toxin producing genes. We assembled high 39 quality transcriptomes of the bufonid...