Organization of the complete mtDNAs of <i>Aix galericulata</i> and <i>Tadorna ferruginea</i>.

<p>Organization of the complete mtDNAs of <i>Aix galericulata</i> and <i>Tadorna ferruginea</i>.</p

Nucleotide composition (%) of some Anseriforme mitochondrial genomes.

<p>Nucleotide composition (%) of some Anseriforme mitochondrial genomes.</p

Phylogenetic relationships among the 16 Anseriforme species based on complete mtDNA sequences.

<p>Numbers at each node are Bayesian posterior probabilities (left) and maximum likelihood bootstrap proportions (estimated from 100 pseudoreplicates) (right).</p

Phylogenetic relationships among the 68 Anseriforme species based on Cyt b, ND2, and COI genes.

<p>Numbers at each node indicate Bayesian posterior probabilities (left) and maximum likelihood bootstrap proportions (from 100 pseudoreplicates) (right).</p

The Complete Mitochondrial Genome of <i>Aix galericulata</i> and <i>Tadorna ferruginea</i>: Bearings on Their Phylogenetic Position in the Anseriformes

<div><p><i>Aix galericulata</i> and <i>Tadorna ferruginea</i> are two Anatidae species representing different taxonomic groups of Anseriformes. We used a PCR-based method to determine the complete mtDNAs of both species, and estimated phylogenetic trees based on the complete mtDNA alignment of these and 14 other Anseriforme species, to clarify Anseriform phylogenetics. Phylogenetic trees were also estimated using a multiple sequence alignment of three mitochondrial genes (Cyt b, ND2, and COI) from 68 typical species in GenBank, to further clarify the phylogenetic relationships of several groups among the Anseriformes. The new mtDNAs are circular molecules, 16,651 bp (<i>Aix galericulata</i>) and 16,639 bp (<i>Tadorna ferruginea</i>) in length, containing the 37 typical genes, with an identical gene order and arrangement as those of other Anseriformes. Comparing the protein-coding genes among the mtDNAs of 16 Anseriforme species, ATG is generally the start codon, TAA is the most frequent stop codon, one of three, TAA, TAG, and T-, commonly observed. All tRNAs could be folded into canonical cloverleaf secondary structures except for tRNASer (AGY) and tRNALeu (CUN), which are missing the "DHU" arm.Phylogenetic relationships demonstrate that <i>Aix galericula</i> and <i>Tadorna ferruginea</i> are in the same group, the Tadorninae lineage, based on our analyses of complete mtDNAs and combined gene data. Molecular phylogenetic analysis suggests the 68 species of Anseriform birds be divided into three families: Anhimidae, Anatidae, and Anseranatidae. The results suggest Anatidae birds be divided into five subfamilies: Anatinae, Tadorninae, Anserinae, Oxyurinae, and Dendrocygninae. Oxyurinae and Dendrocygninae should not belong to Anserinae, but rather represent independent subfamilies. The Anatinae includes species from the tribes Mergini, Somaterini, Anatini, and Aythyini. The Anserinae includes species from the tribes Anserini and Cygnini.</p></div

The genetic distances among the 16 Anseriforme species of mtDNA CR based on kimura-2-parameter model in this study.

<p>Notes: 1: <i>Aix galericulatata</i>, 2: <i>Anas falcata</i>, 3: <i>Anas formosa</i>, 4: <i>Anas platyrhynchos</i>, 5: <i>Anser albifrons</i>, 6: <i>Anser anser</i>, 7: <i>Anser fabalis</i>, 8: <i>Anseranas semipalmata</i>, 9: <i>Aythya americana</i>, 10: <i>Branta canadensis</i>, 11: <i>Cairina moschata</i>, 12: <i>Cygnus atratus</i>, 13: <i>Cygnus columbianus</i>, 14: <i>Dendrocygna javanica</i>, 15: <i>Mergus squamatus</i>, 16: <i>Tadorna ferruginea</i>.</p><p>The genetic distances among the 16 Anseriforme species of mtDNA CR based on kimura-2-parameter model in this study.</p

The 5 Primer sequences used in this study.

<p>Note: M refers to A and C, R refers to A and G.</p><p>The 5 Primer sequences used in this study.</p

The typical amplification results (bands 1–10) of representative sequences from <i>Tadorna ferruginea</i> and <i>Aix galericulata</i>.

<p>Notes: bands 1–6 are the PCR amplification products used primers 6–11 of <i>Tadorna ferruginea</i>, and bands 7–10 are the PCR amplification products used primers 6–9 of <i>Aix galericulata</i>.</p

GenBank accession numbers for the 16 complete mtDNA of Anseriforme species in this study.

<p>GenBank accession numbers for the 16 complete mtDNA of Anseriforme species in this study.</p

GenBank accession numbers (Cyt b, ND2 and COI) for the 68 Anseriforme species in this study.

<p>GenBank accession numbers (Cyt b, ND2 and COI) for the 68 Anseriforme species in this study.</p