Comparative Genomic Analysis Unveils Potential Factors Contributing to the Endangerment of Silurus lanzhouensis

Abstract

Silurus lanzhouensis is a large endemic fish exclusively found in the middle and upper reaches of China’s Yellow River, with a restricted distribution range and a small population size and is listed as an endangered species. To investigate the potential genetic factors contributing to the observed decrease in the population of S. lanzhouensis, we have successfully assembled the first chromosome-level genome of S. lanzhouensis. This genome comprises a total of 30 chromosomes, with a size of 794.43 Mb, and 23,093 protein-coding genes. Comparative genomics analysis reveals that the genetic relationship between S. lanzhouensis and S. meridionalis Chen is the closest, and their common ancestor experienced two rounds of whole genome duplication (WGD) before diverging. Notably, amino acid metabolism-related pathways are enriched in the unique S. lanzhouensis gene family. In addition, we observed that the chemokine receptor and scavenger receptor gene families contracted in S. lanzhouensis, which may be associated with its diminished immune response. Our research findings provide valuable insights into the endangered mechanism of S. lanzhouensis and enhance our understanding of the evolution of Siluriformes fish.