Mitogenomic characterization and phylogenetic placement of the mottled wood-owl strix ocellata with gene rearrangement patterns in strigiformes

Abstract

Owls (order Strigiformes) represent a highly specialized lineage of nocturnal raptors, within which the genus Strix (family Strigidae) comprises several widely distributed species despite the limited availability of comprehensive mitogenomic data. In this study, the complete mitogenome of the Mottled Wood-owl, Strix ocellata (Lesson, 1839), was characterized to investigate its genomic organization, structural features, and patterns of gene rearrangement. Furthermore, the phylogenetic position of S. ocellata was evaluated within the broader lineage of Strigiformes using concatenated mitochondrial protein-coding genes (PCGs), and among congeners using partial COI and Cytb genes. The circular mitogenome of S. ocellata was 19,135 bp in length and comprised the typical vertebrate mitochondrial complement of 13 PCGs, 22 transfer RNA genes (tRNAs), two ribosomal RNA genes (rRNAs), and two non-coding control regions (CRs). The selective pressure analyses revealed strong purifying selection acting across all PCGs, whereas codon usage analysis demonstrated biased synonymous codon preferences, with arginine, leucine, and serine representing the most abundant amino acids. The CR retained the three characteristic conserved domains, while variation in tandem repeat motifs suggested evolutionary divergence among the examined taxa. The phylogenetic inference based on complete mitogenome datasets strongly supported the monophyly of the genus Strix . Notably, S. ocellata occupied a putatively basal position relative to other Strix species based on both complete mitogenomes and partial mitochondrial markers. The comparative examination of mitochondrial gene arrangements revealed a largely conserved genomic architecture across Strigiformes, with observed transposition and duplication events involving ND6, Cytb, several tRNA genes, and the CRs. Collectively, this study provides the first mitogenomic characterization of S. ocellata as well as evolutionary relationships within Strix and the broader Strigiformes lineage. Nevertheless, these findings underscore the need for additional complete mitogenome sequences and whole-genome datasets from broader taxonomic and geographic sampling. Such expanded genomic resources will improve phylogenetic resolution and facilitate a more comprehensive understanding of the evolutionary history and diversification of this owl lineage.