Draft genome of the Antarctic dragonfish, Parachaenichthys charcoti

Background The Antarctic bathydraconid dragonfish, Parachaenichthys charcoti, is an Antarctic notothenioid teleost endemic to the Southern Ocean. The Southern Ocean has cooled to -1.8C over the past 30 million years, and the seawater had retained cold temperature and isolated oceanic environment by Antarctic Circumpolar Current (ACC). Notothenioids dominate Antarctic fish, making up 90% biomass and all notothenioids have undergone molecular and ecological diversification to survive in this cold environment. Therefore, they are considered an attractive Antarctic fish model for evolutionary and ancestral genomic studies. Bathydraconidae is a speciose family of the Notothenioidei, the dominant taxonomic component of Antarctic teleosts. To understand the process of evolution of Antarctic fish, we select a typical Antarctic bathydraconid dragonfish, P. charcoti. Here, we have sequenced, de novo assembled and annotated a comprehensive genome from P. charcoti. Findings The draft genome of P. charcoti is 709 Mb in size. The N50 contig length is 6,145 bp and its N50 scaffold length 178,362 kb. The genome of P. charcoti is predicted to contain 32,712 genes, 18,455 of which have been assigned preliminary functions. A total of 8,951 orthologous groups common to seven species fish were identified, while 333 genes were identified in P. charcoti only; 2,519 orthologous group were also identified in both P. charcoti and N. coriiceps, another Antarctic fish. Four gene ontology (GO) terms were statistically overrepresented among the 333 genes unique to P. charcoti, according to GO enrichment analysis. Conclusions The draft P. charcoti genome will broaden our understanding of the evolution of Antarctic fish in their extreme environment. It will provide a basis for further investigating the unusual characteristics of Antarctic fishes.