Complete Mitochondrial Genome of Turdus merula (Aves: Passeriformes: Turdidae) and Related Species: Genome Characteristics and Phylogenetic Relationships

Mitochondrial genome is a very useful marker for determining the phylogenetic relationships. Hence in this study, the complete mitochondrial genome of Turdus merula was sequenced, described, and analyzed with Sanger sequencing technology. The complete mitochondrial genome of T. merula was 16,734 bp in length and encoded 37 genes, including 13 protein -coding genes, 22 tRNAs, 2 rRNA gene fragments, a control region (D -loop region) and gene arrangement was identical to that of other Passeriformes mitogenomes. The overall base composition included A, 29.34%; C, 32.50%; G, 14.82% and T, 23.34%. The motifs obtained by sequence comparison, "ATGAACCTAA" between ATP8 and ATP6, and "ATGCTAA" between ND4L and ND4, and "CAAGAAAGG" between COXI and tRNA Ser(UCN) were highly conservative in Passeriformes species. The monophyly of Passeriformes is divided into four major clades: Musicicapoidea, Sylvioidea, Passeroidea, and Corvoidea. The phylogeny analyses of Passerida was conducted with the clear support of dividing the group into three superfamilies: the Muscicapoidea, the Sylvioidea, and the Passeroidea, and Passeroidea is a sister taxon for Muscicapoidea and Sylvioidea, which are closely related to each other. We suggest that the genus Paradoxornis will be classified as family Sylviidae, while these two species ( Luscinia cyanura and Monticola gularis ) are placed in the family Muscicapidae. Moreover, Turdidae formed a sister group with Muscicapidae, which indicates that they are closely related and form the superfamily Muscicapoidea together with the Sturnidae families. The relationships between some species of the order Passeriformes may remain difficult to resolve despite an effort to collect additional characters for phylogenetic analysis. Current research of avian phylogeny should focus on adding molecular markers and taxa samples and use both effectively to reconstruct a better resolution for disputed species.