Abstract
In this study, we sequenced and characterized the complete mitochondrial genome of Green-winged macaw (Ara chloropterus) listed on CITES Appendix II. The circular double-stranded genome was 16,991 bp in size and included 22 transfer RNA (tRNA) genes, 13 protein-coding genes (PCGs), two ribosomal RNA genes (rrnL and rrnS), and one non-coding control region (D-loop). Both order and arrangement of genes were identical to those of other animal mitogenomes. The base content was 30.00% A, 14.38% G, 23.27% T, and 32.35% C, with an A + T content of 53.37%. Furthermore, phylogenetic analysis indicated that A. chloropterus is closely related to the Blue and yellow macaw (A. ararauna).
Keywords: Green-winged macaw (Ara chloropterus), mitochondrial genome, phylogenetic analysis
The Green-winged macaw (Ara chloropterus) is a kind of large Ara macaws (Forshaw 2010), which belongs to subfamily Arinae (Neotropical Parrots). Although this bird is listed as of least concern, the population is currently decreasing as a result of ongoing habitat destruction and unsustainable levels of exploitation (BirdLife International 2019). In order to better protect the species, A. chloropterus was listed in CITES Appendix II, owing to its association with wild animal trade. Herein, the complete mitogenome of A. chloropterus was determined.
A feather sample was collected from Hongshan Zoo (N32°09′, E118°08′). The voucher specimen (A-2019003) was stored in the Key Laboratory of Wildlife Evidence Technology State Forest and Grassland Administration. Total DNA was extracted using a Universal Genomic DNA Extraction Kit (Takara, Beijing, China). PCR primers were designed based on known sequences of A. ararauna (GenBank accession no. KF010315.1) and A. glaucogularis (GenBank accession no. JQ782215.1). PCR-amplified fragments were subjected to Sanger sequencing and then assembled into a complete mitogenome sequence, submitted to GenBank (accession no. MN604694).
As in other multicellular animals (Bridge et al. 1992), the double-stranded mitogenome of A. chloropterus was circular, ∼16 kb in length (16,991 bp to be exact), and contained two ribosomal RNA genes (rrnL and rrnS), 13 protein-coding genes (PCGs), 22 transfer RNA (tRNA) genes, and a single non-coding control region. Meanwhile, the gene arrangement of the species’ mitogenome was identical to that of other birds (Lan et al. 2019; Liu et al. 2019).
Furthermore, the nucleotide composition of the mitogenome was 30.00% A, 14.38% G, 23.27% T, and 32.35% C, with an A + T content of 53.37%. Among the PCGs, nad5 (1809 bp) and atp8 (168 bp) were the longest and shortest, respectively, and ATG was the most prevalent start codon, whereas TAA was the most prevalent stop codon. The lengths of rrnL and rrnS were 972 and 1567 bp, respectively. The two genes were located in between trnF and trnL2 and were separated by trnV. In addition, the A. chloropterus mitogenome contained 22 tRNAs, which ranged in size from 66 to 76 bp, interspersed throughout the genome. In A. ararauna, the 1487 bp D-loop was located between trnE and trnF, and the A + T content (57.70%) was higher than the G + C content (42.30%) and the full sequence A + T content (53.37%).
In order to investigate the phylogenetic relationships between A. chloropterus and other parrot species, we constructed a neighbour-joining phylogenetic tree using MEGA 7.0 under the Kimura 2-parameter model with 1000 bootstrap replicates (Kumar et al. 2016). The analysis was based on the whole mitogenome sequences of A. chloropterus, 14 other species from Order Psittaciformes, and 2 species from Order Passeriformes, which were used as outgroups. The topologies of molecular phylogenetic analysis showed that target species A. chloropterus was placed as sister to A. ararauna, which, together, were closely related to other macaws, namely, Primolius couloni and Orthopsittaca manilata (Figure 1). The present study generated the complete mitogenome of A. chloropterus and provides fundamental genetic information for the species’ conservation.
Figure 1.
Phylogenetic tree based on the mitogenome of 17 species.
Funding Statement
This study was supported by the Jiangsu Planned Projects for Postdoctoral Research Funds [No. 2018K064B].
Disclosure statement
The authors report no conflicts of interest. The sequence has been submitted to NCBI under the accession no. MN604694.
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