THE COMPLETE MITOCHONDRIAL GENOME OF GOBIO ACUTIPINNATUS AND PHYLOGENETIC ANALYSIS OF GOBIONINAE SUBFAMILY

<italic>Gobio acutipinnatus</italic> is a native and unique fish species in the Irtysh River Basin, as an important food source for carnivorous fish, it plays a crucial role in maintaining the biodiversity and ecological balance of the region. In order to understand the mitochondrial genome of <italic>G. acutipinnatus</italic> and clarify its phylogenetic position in the subfamily Gobioninae, we sequenced its complete mitochondrial genome and constructed a molecular phylogenetic tree of Gobioninae based on nucleotide sequences of 13 protein-coding genes. The results showed that the complete mitochondrial genome of <italic>G. acutipinnatus</italic> was 16608 bp in length, consisting 13 protein-coding genes, 2 rRNA genes, 22 tRNA genes, 1 non-coding region, and 1 origin of light-strand replication (OL) region. The base composition exhibits a significant AT preference (A+T=54.90%). Except for the protein-coding gene <italic>nad6</italic> and 8 tRNA genes (<italic>trnQ</italic>, <italic>trnA</italic>, <italic>trnN</italic>, <italic>trnC</italic>, <italic>trnY</italic>, <italic>trnS2</italic>, <italic>trnE</italic>, and <italic>trnP</italic>) located outside the light chain, the remaining 28 genes were all located in the heavy chain. Among the 22 tRNA genes, only <italic>trnS1</italic> gene lacked the DHU arm, while the other tRNAs could fold into the standard cloverleaf secondary structure, with a total of 57 G-U mismatches pairs. The phylogenetic tree (based on 13 protein-coding genes) revealed that the genus <italic>Saurogobio</italic> was embedded within <italic>Gobio</italic>, together with <italic>Mesogobio</italic> and <italic>Acanthogobio</italic>, they formed a branch. <italic>Gobio acutipinnatus</italic> clustered with <italic>Gobio occitaniae</italic>, <italic>Gobio cynocephalus</italic>, <italic>Gobio lozanoi</italic>, <italic>Gobio macrocephalus</italic>, <italic>Gobio soldatovi</italic>, and <italic>Gobio gobio</italic> within the genus <italic>Gobio</italic>. This study is the first to clarify the structural characteristics of the complete mitochondrial genome of <italic>G. acutipinnatus</italic> and determine its phylogenetic position, providing key molecular evidence for understanding the taxonomic relationships of this species within the genus <italic>Gobio</italic> and the Gobioninae subfamily.