Characterization and phylogenetic analysis of the complete mitochondrial genome of Aythya marila

Abstract

Abstract In this study, we sequenced and annotated the complete mitochondrial genome of Aythya marila, which contained 22 tRNAs, 13 protein-coding genes, two ribosomal RNAs, and one D-loop, with a length of 16617 bp. The sizes of the PCGs ranged from 297 to 1824 bp, and all PCGs, except ND6, were located on the heavy chain (H). ATG and TAA were the most common start and termination codons of the 13 PCGs, and the fastest-evolving gene was ATP8, whereas the slowest-evolving gene was COI. Codon usage analysis indicated that CUA, AUC, GCC, UUC, CUC, and ACC were the six most frequent codons. The nucleotide diversity values indicated a high level of genetic diversity in Aythya marila. FST analysis suggested that there was widespread gene exchange between A. baeri and A. nyroca. Phylogenetic reconstructions using the mitochondrial genomes of all available Anatidae species showed that four major clades among Anatidae: Dendrocygninae, Oxyurinae, Anserinae, and Anatinae, in addition to A. marila, were closely related to A. fuligula. In general, this research will provide valuable information on the evolution of A. marila and therefore provide new insights into the phylogeny of Anatidae.