Chromosome-Scale Genome Assembly and Genome-Wide Identification of Antimicrobial Peptide-Containing Genes in the Endangered Long-Finned Gudgeon Fish (Rhinogobio ventralis)

As an economically important species endemic to the upper tributaries of Yangtze River in China, long-finned gudgeon fish (<i>Rhinogobio ventralis</i>) has been classified as endangered due to habitat destruction and population decline. In this study, we constructed a chromosome-level genome assembly of <i>R. ventralis</i> by integration of MGI, PacBio and Hi-C sequencing technologies. The final genome assembly was 1015.9 Mb in length (contig N50: 25.91 Mb; scaffold N50: 39.99 Mb), and 97.19% of the haplotypic genome sequences were anchored onto 25 chromosomes. Repetitive elements accounted for 51.00% of the entire genome assembly. A total of 23,220 protein-coding genes were predicted for the assembled genome, of which 99.79% were functionally annotated. Genome evaluation revealed 99.72% completeness for the genome assembly. Through genome-wide prediction of antimicrobial peptides (AMPs), we identified and localized 561 putative AMP-containing genes in the <i>R. ventralis</i> genome. These genes were further classified into 185 distinct functional categories based on public databases, with the top ten components of Penetratin (21.74%), Histone (5.70%), E6AP (4.09%), Scolopendin 1 (2.67%), D38 (2.31%), WBp-1 (2.13%), Defensin (2.13%), Claudin 1 (1.96%), Azurocidin (AZU1, 1.78%), and Ubiquitin (1.60%). Our data presented here provide a potential genetic resource for promoting fundamental research and wild population conservation of this endangered fish species.