Inference of a genome-wide protein-coding gene set of the inshore hagfish Eptatretus burgeri

Abstract

The hagfishes (Myxiniformes) arose from agnathan (jawless vertebrate) lineages and they are one of only two extant cyclostome taxa, together with lampreys (Petromyzontiformes). Even though whole genome sequencing has been achieved for diverse vertebrate taxa, genome-wide sequence information has been highly limited for cyclostomes. Here we sequenced the genome of the inshore hagfish Eptatretus burgeri using DNA extracted from the testis, with a short-read sequencing platform, aiming to reconstruct a high-coverage protein-coding gene catalogue. The obtained genome assembly, scaffolded with mate-pair reads and paired RNA-seq reads, exhibited an N50 scaffold length of 293 Kbp, which allowed the genome-wide prediction of coding genes. This computation resulted in the gene models whose completeness was estimated at the complete coverage of more than 83 % and the partial coverage of more than 93 % by referring to evolutionarily conserved single-copy orthologs. The high contiguity of the assembly and completeness of the gene models promise a high utility in various comparative analyses including phylogenomics and phylome exploration.