Complete Mitochondrial Genomes of Three Nuthatches From the Genus Sitta (Aves: Passeriformes: Sittidae) and Mitogenome-Based Phylogenetic Analysis

Abstract Background Nuthatches (genus Sitta) comprise a group of Passeriformes. With the publication of more mitochondrial genome data, there has been considerable focus on the taxonomic status of the nuthatches. To understand the phylogenetic position of Sitta and phylogenetic relations within this genus, we sequenced and analyzed the complete mitochondrial genomes of three species, S. himalayensis, S. nagaensis and S. yunnanensis, making this the first account of complete mitochondrial genomes (mitogenomes) for this genus. Results The mitochondrial genomes of three Sitta species are 16,822-16,830 bp in length and consisted of 37 genes and a control region. This study recovered the same gene arrangement found in the mitogenomes of Gallus gallus, which is considered the typical ancestral avian gene order. All tRNAs were predicted to form the typical cloverleaf secondary structures. Bayesian inference and maximum likelihood phylogenetic analyses of sequences of 18 species obtained a well-supported topology. The family Sittidae is the sister-group of Troglodytidae, and the genus Sitta can be divided into 3 major clades. We demonstrated the phylogenetic relationships within genus Sitta (S. carolinensis + (S. villosa + S. yunnanensis + (S. himalayensis + (S. europaea + S. nagaensis)))).