Liver transcriptome characterization of the endangered freshwater silverside Basilichthys microlepidotus (Teleostei: Atherinopsidae) using next generation sequencing

Twenty eight out of 44 Chilean freshwater fishes have been considered to fall within the vulnerable or threatened category. Thus, information about the biology, ecology and the effects of the anthropic activity on these species is fundamental to take appropriate conservation measures. In Chile the endemic silverside Basilichthys microlepidotus inhabits mainly rivers surrounded by cities; during the last 10 years it was categorized as an endangered species, thus more basic information is needed in order to elaborate a plan of protection for this species. To this end, the transcriptome of B. microlepidotus was sequenced, assembled and characterized. A total of 7.8 million reads (1.05 Gb) were obtained from the sequencing and 5.93 million reads (0.83 Gb) were used for the de novo assembly, obtaining a total of 31,523 contigs. Of these, 13,724 contigs with expression in all the individuals used were retained for the functional annotation. 7938 sequences were successfully annotated; the biological processes class was the most highly represented, followed by molecular function and cellular component. These sequence data provide a useful new molecular resource for future studies on gene expression and the effects of the human activity on B. microlepidotus, which will facilitate obtaining more information about that, as well as the developing of appropriate conservation strategies for this species.