The reference genome of the selfing fish Kryptolebias hermaphroditus: Identification of phases I and II detoxification genes.

The selfing fish Kryptolebias hermaphroditus has unique reproductive system for self-fertilization, making genetically homozygous offsprings. Here, we report on high density genetic map-based genome assembly for the K. hermaphroditus Panama line (PanRS). The numbers of scaffolds were 5212 and the genome was 683,992,224 bp (N50 = 27.45 Mb). The length of anchored scaffold onto 24 linkage groups was 652,231,070 bp (95.3% of genome) with 0.01% of the gap and 39.33% of GC content and complete Benchmarking Universal Single-Copy Orthologs value was 96.6%. The numbers of annotated genes were 36,756 (average gene length 1368 bp) with the GC content of 54.1%. To examine the difference between the two sister species in the genus Kryptolebias, we compared the genomes of K. hermaphroditus PanRS and Kryptolebias marmoratus PAN line on the composition of transposable elements. To demonstrate applications of genome library, phase I and II detoxification related gene families have been analyzed, and compared the syntenies containing loci of CYP and GST genes on linkage groups. This K. hermaphroditus genome information will be helpful for a better understanding on genome-wide mechanistic view of detoxification and antioxidant-related genes over evolution in the view of fish environmental ecotoxicology.