Abstract
Amphibians are important vertebrates in toxicology often representing both aquatic and terrestrial forms within the life history of the same species. Of the thousands of species, only two have substantial genomics resources: the recently published genome of the Pipid, Xenopus (Silurana) tropicalis, and transcript information (and ongoing genome sequencing project) of Xenopus laevis. However, many more species representative of regional ecological niches and life strategies are used in toxicology worldwide. Since Xenopus species diverged from the most populous frog family, the Ranidae, ~200 million years ago, there are notable differences between them and the even more distant Caudates (salamanders) and Caecilians. These differences include genome size, gene composition, and extent of polyploidization. Application of toxicogenomics to amphibians requires the mobilization of resources and expertise to develop de novo sequence assemblies and analysis strategies for a broader range of amphibian species. The present mini-review will present the advances in toxicogenomics as pertains to amphibians with particular emphasis upon the development and use of genomic techniques (inclusive of transcriptomics, proteomics, and metabolomics) and the challenges inherent therein.
Highlights
Amphibians are important vertebrates in toxicology often representing both aquatic and terrestrial forms within the life history of the same species
The X. laevis metamorphosis assay (XEMA) assay has been adapted for X. tropicalis (Mitsui et al, 2006) and served as a template for the development of some native frog metamorphosis assays for R. rugosa (Oka et al, 2009), Bombina orientalis (Park et al, 2010), and Pseudacris regilla (Marlatt et al, submitted)
The recommended XEMA assay relies upon morphological criteria and the input of toxicogenomic endpoints is not standard practice
Summary
Amphibians are important vertebrates in toxicology often representing both aquatic and terrestrial forms within the life history of the same species. Recent amphibians are comprised of three orders: Anura (frogs and toads), Caudata (salamanders), and Gymnophiona (caecilians; Dubois, 2004; Frost et al, 2006), of which ∼90% of species are Anura. The remaining 10% of records comprise terrestrial exposures of frog, toad, and salamander species (US EPA, 2012).
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
