Whole-genome sequence of the eastern spadefoot toad, Scaphiopus holbrookii (Amphibia: Anura: Scaphiopodidade) and of the Maldonado redbelly toad, Melanophryniscus moreirae (Amphibia: Anura: Bufonidae)

Abstract

Despite the availability of second-generation sequencing technologies that allows rapid acquisition of molecular data at feasible prices, computational difficulties in analyzing large sequence datasets and the lack of reference genomes for frogs have posed difficulties to the advance of anuran genomics. To date, only two whole-genomes and 81 complete mitochondrial genomes have been published for Anura, a very small representation of the current 6482 species of frogs. Here I propose to assemble and analyze the partial nuclear and complete mitochondrial genome of the Eastern spadefoot toad, Scaphiopus holbrookii (Scaphiopodidae), and of the Maldonado redbelly toad, Melanophryniscus moreirae (Bufonidae), using second-generation sequencing technology (Illumina HiSeq). These species have been selected due to their tractable genetics in relation to other species of Anura and Bufonidae, respectively. Also, both species can allow us to address specific questions regarding amphibian evolution and their chemical defensive mechanisms. The Eastern spadefoot have strategic phylogenetic positions, which might allow us to ask questions about genome evolution at the aquatic to terrestrial transition in frogs, the role of transposable elements in amphibian genome sizes, lineage- and anuran-specific highly-conserved elements, the evolution of organelle genes and mitochondrial genome arrangements in Anura, among others. The Maldonado redbelly toad is a bufonid in which large quantities of dietary alkaloids and the biosynthesized indolealkylamine bufotenine co-occur, which makes it strategic to our understanding of anuran chemical defense. The viability of this project will be guaranteed by the availability of raw sequences, massive computational resources and the expert collaboration that I will receive at the foreign institution. I hope this project will take us one step further in overcoming both our current lack of knowledge in anuran genomics and the gap between the easy gathering of second-generation sequencing data and the computational difficulties in analyzing it. (AU)