Draft genome of the Antarctic dragonfish, Parachaenichthys charcoti

Abstract

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 P. charcoti has undergone molecular and ecological diversification to survive in this cold environment. However, little is known about the biology of this species, except that globin intergenic regulatory regions play a role in its low levels of alpha-globin expression. To understand the process of evolution of Antarctic fish, we sequenced and annotated the P. charcoti genome. Findings The draft genome of P. charcoti is 709 Mb in size. The N50 contig length is 6,246 bp and its N50 scaffold length 166,726 kb, with a GC content of 40.66%. 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.