The Determination Of Four Tits Mitochondrial Genome And Passeriformes Birds System Research

In order to study the structure and sequence characters of mitochondrial genome in Passeriformes and reconstruct the phylogenetic relationship among major groups of Passeriformes, the complete mitochondrial genomes of Parus spilonotus, Parus dichrous, Parus songarus and Parus montanus baicalensis were sequenced using the long PCR amplification and primer walking method. Based on the different partition datasets, the phylogeny of51Passeriformes species (including38species from NCBI and13species sequenced in our laboratory) with outgroup of4species in Anseriformes, was reconstructed using different phylogenetic methods. Meanwhile, divergence times of major lineages were estimated with Bayesian dating. The conclusions show from the study as follows:1. The complete mitochondrial genomes of Parus spilonotus, Parus dichrous, Parus songarus and Parus montanus baicalensis are16768bp,16800bp,16783bp and16783bp in length, respectively. There are showing a typical vertebrate pattern with13protein coding genes,22transfer RNAs genes (tRNAs), two ribosomal RNAs (12S rRNA and16S rRNA) and one major non-coding region.2. The ND6gene and eight tRNAs(trnaA, trnaS, trnaC, trnaE, trnaN, trnaQ, trnaY and trnaP) were coding by light strand. The rest of28genes were coding by heavy strand in mitochondrial genome of four species. The gene order for mitochondrial genome is the same as other species. There are no indel and inversion among these four genomes.3. The AT and GC content of PCGs, rRNA, tRNAs and control region in mitochondrial genome of this four species has not significently biased statistically. There are five amino acids (Leu, Thr, Ala, He and Ser) composition of highest frequency, accounted for almost50%of all amino acids.4. All the tRNA genes in mitochondrial genomes of Parus spilonotus, Parus dichrous, Parus songarus and Parus montanus baicalensis have the typical clover leaf structure except the tRNASer(AGN), which is lack of the DHU arm in their secondary structure. The secondary structure of tRNAArg, tRNAVal and tRNAlle are extremly conservative, and no mispair exists in stem, but the others all have mispair, most G-U mispair from the secondary structure in all four species.5. The secondary structures of complete rRNAs have been predicted for these four species. Most parts of the secondary structure are conserved and the main differences took place in terminal regions. There are4domains,47-48helices structures in12S rRNA, and6domains,55-60helices structures in16S rRNA. 6. Length heteroplasmy in the hypervariable region of mitochondrial DNA (mtDNA) in Parus spilonotus was analyzed by direct sequencing, fragment analysis and cloning.7. Phylogenetic analyses (BI and ML) based on the complete mitochondrial genome, PCGs data sets and12S rRNA data sets arrived at the similar topology. The phylogenetic trees from different methods and data sets support that Passeriformes divide two groups Passeri and Tyranni, and Passerj include the Corvida and Passerida. The result shows that the monophyly of Paridae can be supported while the monophyly of Sylvioidea is rejected; Aegithalos as a section level separately in Passeriformes and the relationship is colsely with Hirundinidae. Our results suggest the promotion of the genus to a separate family. The positions of Menuridae were uncertain based on the three date sets, and the phylogenetic relationships of other major groups were rather robust.8. The origin of the Passeriformes as the monophyly is estimated at23.01Ma (95%HPD13.94-23.63Ma) in the early Miocene, and later divergence of two major clad are Oscine and Suboscine occurred17.72Ma (95%HPD9.61-17.74Ma) in Burdigalian of Miocene. The divergence of Corvida and Passerida occurred13.84Ma (95%HPD9.18-14.56Ma) in late Miocene. The quick radiation of the tits range from the late Miocene to the Pleistocene (from5.85to3.58Ma), and this may be related with the western orogenic movement.