Chromosome-level genome assemblies of five Sinocyclocheilus species

Abstract

Sinocyclocheilus, a genus of tetraploid fishes, is endemic to the karst regions of Southwest China. All species within this genus are classified as second-class national protected species due to their unique and fragile habitat. However, absence of high-quality genomic resources has hindered various research efforts to elucidate their phylogenetic relationships and the origin of polyploidy. To address these academic challenges, we at first constructed a high-quality genome assembly for the most abundant representative, golden-line barbel (Sinocyclocheilus grahami), by integration of PacBio long-read and Hi-C sequencing technologies. The final scaffold-level genome assembly of S. grahami is 1.6 Gb in length, with a scaffold N50 up to 30.7 Mb. A total of 42,205 protein-coding genes were annotated. Subsequently, 93.1% of the assembled genome sequences (about 1.5 Gb) and 93.8% of the total predicted genes were successfully anchored onto 48 chromosomes. Furthermore, we obtained chromosome-level genome assemblies for four other Sinocyclocheilus species (including S. anophthalmus, S. maitianheensis, S. anshuiensis, and S. rhinocerous) based on homologous comparison. These genomic data we present in this study provide valuable genetic resources for in-depth investigation on cave adaptation and improvement of economic values and conservation of diverse Sinocyclocheilus fishes.