Transcriptome pyrosequencing of the Antarctic brittle star Ophionotus victoriae
Ophiuroids are part of a wide range of species that are contributing to improved understanding in the medically important area of tissue regeneration. All brittle stars regenerate lost limbs, but the rate at which this occurs is highly variable and species-specific. One of the slowest rates of arm regeneration reported is that of Antarctic Ophionotus victoriae. Additionally O. victoriae also has an unusual delay in the onset of regeneration of about 5 months. Both processes are of interest for the areas of regeneration biology and adaptation to the cold environments. One method of understanding the details of the regeneration processes in brittle stars is to characterise the genes involved. In the largest transcriptome study of any ophiuroid to date, we describe the results of mRNA pyrosequencing from pooled samples of regenerating arms of O. victoriae. The sequencing reads resulted in 18,000 assembled contiguous sequences of which 19% were putatively annotated by blast sequence similarity searching. We focus on the identification of major gene families and pathways with potential relevance to regeneration processes including Wnt/ß-catenin pathway, Hox genes, TGF beta signalling, SOX gene family and Notch signalling. These data significantly increase the amount of ophiuroid sequences publicly available and will provide candidate transcripts for further investigation of the unusual regenerative process in this Antarctic ophiuroid.