First Ever Whole Genome Sequencing and De Novo Assembly of the Freshwater Angelfish, Pterophyllum scalare

Abstract

This research work is the first to ever sequence and perform a de novo assembly of the genome of the freshwater angelfish, Pterophyllum scalare . The final genome assembly consisted of 15,486 contigs and was 734.79 Mb in size with an 86.5% BUSCO score. Functional annotation of the genome revealed 24,247 protein-coding sequences related to other fish species. 14,329 (59%) of the identified genes were orthologous to Archocentrus centrarchus , a closely related South American cichlid.

Figure 1. Long-read nanopore sequencing of angelfish DNA leads to a robust genome assembly:

A) Table depicting the read statistics of the nanopore sequencing including the number of collected reads, the mean read length, and mean read quality. B) Angelfish mitochondrial genome annotated with the 37 genes. Violet text refers to tRNAs, red text refers to protein-coding genes, and blue text corresponds to rRNAs. The green histogram indicates + GC skew while the purple histogram indicates -GC skew. C) Snail plot showing the assembled nuclear genome with its corresponding statistics. D) Orthologous genes were most commonly identified in the following organisms: Archocentrus centrarchus , Oreochromis niloticus, Oreochromis aureus, Astatotilapia calliptera , and Simochromis diagramma .