Complete mitochondrial genome of the Red-billed Starling,Sturnus sericeus(Aves: Passeriformes): The first representative of the family Sturnidae with a single control region

Sturnidae sensu lato Mitogenomics: Novel Insights into Codon Aversion, Selection, and Phylogeny

The Sturnidae family comprises 123 recognized species in 35 genera. The taxa Mimidae and Buphagidae were formerly treated as subfamilies within Sturnidae. The phylogenetic relationships among the Sturnidae and related taxa (Sturnidae sensu lato) remain unresolved due to high rates of morphological change and concomitant morphological homoplasy. This study presents five new mitogenomes of Sturnidae sensu lato and comprehensive mitogenomic analyses. The investigated mitogenomes exhibit an identical gene composition of 37 genes-including 13 protein-coding genes (PCGs), 2 rRNA genes, and 22 tRNA genes-and one control region (CR). The most important finding of this study is drawn from CAM analyses. The surprisingly unique motifs for each species provide a new direction for the molecular species identification of avian. Furthermore, the pervasiveness of the natural selection of PCGs is found in all examined species when analyzing their nucleotide composition and codon usage. We also determine the structures of mt-tRNA, mt-rRNA, and CR structures of Sturnidae sensu lato. Lastly, our phylogenetic analyses not only well support the monophyly of Sturnidae, Mimidae, and Buphagidae, but also define nine stable subclades. Taken together, our findings will enable the further elucidation of the evolutionary relationships within Sturnidae sensu lato.

Molecular identification and phylogenetic analysis of the mitogenome in endangered giant nuthatch Sitta magna (Passeriformes, Sittidae)

The Giant Nuthatch Sitta magna (family Sittidae) is a passerine bird, the quantification of the number of habitats and species on a global scale remains low. Most species are restricted to low elevations in southwest China, eastern Myanmar, and northern Thailand. To characterize the mitochondrial genome sequence of S. magna and its phylogenetic relationships with other members within the genus Sitta, the mitochondrial genome of S. magna was sequenced using the whole genome shotgun method. The sequencing results showed that the mitochondrial genome was 16,829 bp long and consisted of 13 protein-coding genes (PCGs), 22 transfer RNA genes (tRNAs), 2 ribosomal RNA genes (rRNAs), and one control region (D-loop). All tRNAs were predicted to form a typical clover secondary structure. Among the 13 PCGs, only the start codon in COI was ATC, the start codon by the remaining 12 PCGs was ATG, and the stop codons were TAG, TAA, AGG, AGA, and TA. Bayesian inference and maximum likelihood phylogenetic analysis of the sequences of 17 species generated consistent well-supported phylogenies. The family Polioptilidae and the family Troglodytidae were closely related, and the family Sittidae was confined to a single branch. The genus Sitta in the family Sittidae was mainly clustered into three branches. Our findings provide new mitochondrial genomic data that could be used for phylogenetic and taxonomic studies; our results also certificate into the phylogenetic relationships within the genus Sitta ((S. himalayensi+(S. nagaensis + S. europaea))+(S. villosa + S. yunnanensis))+(S. carolinensis + S. magna).

The complete mitochondrial genomes of Tarsiger cyanurus and Phoenicurus auroreus: a phylogenetic analysis of Passeriformes

Passeriformes is the largest group within aves and the phylogenetic relationships between Passeriformes have caused major disagreement in ornithology. Particularly, the phylogenetic relationships between muscicapoidea and sylvioidea are complex, and their taxonomic boundaries have not been clearly defined. Our aim was to study the status of two bird species: Tarsiger cyanurus and Phoenicurus auroreus. Furthermore, we analyzed the phylogenetic relationships of Passeriformes. Complete mitochondrial DNA (mtDNA) sequences of both species were determined and the lengths were 16,803 (T. cyanurus) and 16,772 bp (P. auroreus), respectively. Thirteen protein-coding genes, 22 tRNA genes, two rRNA genes, and one control region were identified in these mtDNAs. The contents of A and T at the base compositions was significantly higher than the content of G and C, and this AT skew was positive, while the GC skew was negative. The monophyly of Passeriformes is divided into four major clades: Corvoidea, Sylvioidea, Passeroidea, and Musicicapoidea. Paridae should be separated from the superfamily Sylvioidea and placed within the superfamily Muscicapoidea. The family Muscicapidae and Corvida were paraphyly, while Carduelis and Emberiza were grouped as a sister taxon. 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 characters and taxa and use both effectively to obtain a better resolution for deeper and shallow nodes.

Complete mitochondrial genome of the Black-capped Bulbul, Pycnonotus melanicterus (Passeriformes: Pycnonotidae)

The first complete maternally-inherited mitochondrial genome of Pycnonotus melanicterus has been sequenced and annotated in this study. The mitogenome is 17,011 bp in size with an A+T content of 55.15%, consisting of 13 protein-coding genes (PCGs), 22 transfer RNA (tRNA) genes, 2 ribosomal RNA (srRNA and lrRNA) genes, and 2 extensive heteroplasmic control regions. Genome organization and gene arrangements of P. melanicterus are similar to those of other bulbuls. All 13 PCGs initiated with ATG as the start codon, while terminated by seven types of stop codons. All tRNA genes sequences have the potential to fold into typical cloverleaf secondary structures. Gene overlapping was observed in the P. melanicterus mitogenome. Moreover, our results of phylogenetic analysis well support the monophyly of Pycnonotidae as previously studies.

Sequencing and phylogenetic analysis of the Pyrgilauda ruficollis (Aves, Passeridae) complete mitochondrial genome

In this study, both long PCR and conserved primers walking sequencing methods were used to determine the complete sequence of the of Pyrgilauda ruficollis mitochondrial genome (KC836121). The results showed that the complete mitochondrial genome of P. ruficollis is 1 6909 bp in length with 55.0% A+T content, harboring the typical 37 genes. The mitogenome had the same gene order with that of Podoces hendersoni. All protein coding genes started with ATG codon, except ND3 with GTG. For the stop codon usage, most genes terminate with codons TAA or TAG, but ND5 terminated with AGA, while ND1 and COI genes with AGG, and both the genes COⅢ and ND4 have an incomplete termination codon (T). The secondary structures of 22 tRNA genes were also predicted, showing that all tRNAs can form typical clover-leaf secondary structures, except for the tRNA(Ser) (AGN) which loses the DHU arm, while tRNA(Phe) harbor an extra nucleotide inserted in the TψC arm. The predicted secondary structures of 12S rRNA and 16S rRNA exhibit 47 helices in 4 domains and 60 helices in 6 domains respectively. The control region of P. ruficollis with the length of 1 305 bp was located between tRNA(Glu) and tRNA(Phe), and typical domains of which could be found as other bird groups. Using the data from 13 mitochondrial protein-coding genes, results of a final phylogenetic analysis strongly supports the traditional view that P. ruficollis is closely related with Passeridae and Fringillidae.