Research Article |
Corresponding author: Hongyi Liu ( hongyi_liu@njfu.edu.cn ) Academic editor: George Sangster
© 2021 Nan Xu, Jiayu Ding, Ziting Que, Wei Xu, Wentao Ye, Hongyi Liu.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Xu N, Ding J, Que Z, Xu W, Ye W, Liu H (2021) The mitochondrial genome and phylogenetic characteristics of the Thick-billed Green-Pigeon, Treron curvirostra: the first sequence for the genus. ZooKeys 1041: 167-182. https://doi.org/10.3897/zookeys.1041.60150
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Members of the genus Treron (Columbidae) are widely distributed in southern Asia and the Indo-Malayan Region but their relationships are poorly understood. Better knowledge of the systematic status of this genus may help studies of historical biogeography and taxonomy. The complete mitochondrial genome of T. curvirostra was characterized, a first for the genus. It is 17,414 base pairs in length, containing two rRNAs, 22 tRNAs, 13 protein coding genes (PCGs), and one D-loop with a primary structure that is similar to that found in most members of Columbidae. Most PCGs start with the common ATG codon but are terminated by different codons. The highest value of the Ka/Ks ratio within 13 PCGs was found in ATP8 with 0.1937, suggesting that PCGs of the mitochondrial genome tend to be conservative in Columbidae. Moreover, the phylogenetic relationships within Columbidae, which was based on sequences of 13 PCGs, showed that (T. curvirostra + Hemiphaga novaeseelandiae) were clustered in one clade, suggesting a potentially close relationship between Treron and Hemiphaga. However, the monophyly of the subfamilies of Columbidae recognized by the Interagency Taxonomic Information System could not be corroborated. Hence, the position of the genus Treron in the classification of Columbidae may have to be revised.
Columbidae, genome sequencing, Ka/Ks ratio, mitochondrial DNA, phylogenetic tree
Mitochondrial DNA sequences can be reliable markers for studying the origin and phylogenetic relationships of species owing to its fast evolution rate, simple structure, light molecular weight, and maternal inheritance (
The pigeons and doves (family Columbidae) are widely distributed on all continents except Antarctica, ranging from tropical to temperate regions (
All species of green-pigeons (Treron) are listed as second-class national protected animals under China’s Catalog of Wildlife of the Key State Protection. Most species in the genus are declining (
The Thick-billed Green-Pigeon Treron curvirostra (Gmelin, 1789) is mainly distributed in virgin, evergreen, broad-leaved, and secondary forests of the tropical and subtropical hilly zone in Southeast Asia and South Asia (
To understand the systematic position of the genus Treron among Columbidae, we sequenced and characterized the first complete mitochondrial genome sequence of T. curvirostra. We compared the complete mitochondrial genome of T. curvirostra with that of 33 other pigeons and doves and determined its genetic structural characteristics. In addition, we used 13 protein-coding genes (PCGs) to reconstruct a phylogenetic tree, which we use to infer the taxonomic position of the species and illuminate the phylogenetic relationships among species of Columbidae.
This study was authorized by Nanjing Forestry University. The youngest tail feathers of a male Thick-billed Green-Pigeon T. curvirostra were collected from an individual rescued from a net that was used to prevent birds from stealing fruit at the Xieyang peak of Dali City, Yunnan Province, China. The bird was identified as T. curvirostra based on its morphological characters (
Primers were designed based on the mitochondrial gene sequences of Streptopelia decaocto, Hemiphaga novaeseelandiae, and Columba hodgsonii (GenBank accession numbers KY827036, EU725864, and MN919176,respectively) using DNASTAR software (DNASTAR, USA;
Fragment | Region | Primer pair | Primer sequence (5' - 3') |
---|---|---|---|
DG 1 | COI-COII | DG 1F | CACTCAGCCATCTTACCT |
DG 1R | ACAGATTTCTGAGCATTGGC | ||
DG 2 | COII-ND4 | DG 2F | CCAATCCGCATCATCGTC |
DG 2R | GGTTTCCTCATCGTGTGA | ||
DG 3 | ND4-ND5 | DG 3F | CAGCCTCCTAATTGCCAC |
DG 3R | GTAGGGCGGAGACTGGAG | ||
DG 4 | ND5-Cyt b | DG 4F | ACAGGGCCGAGCAGAAGC |
DG 4R | TAGGAAGTATCACTCTGG | ||
DG 5 | Cyt b-12S rRNA | DG 5F | GCAGGCCTCACCATTATCC |
DG 5R | GTTAATTACTGCTGAGTACC | ||
DG 6 | 12S rRNA-16S rRNA | DG 6F | GCTGGCATCAGGCACGCC |
DG 6R | TGGGTCTGGTTACTGTTA | ||
DG 7 | 16S rRNA-ND2 | DG 7F | CGGTTGGGGCGACCTTGGAG |
DG 7R | AGAGTGGGAGGAGTAGGGC | ||
DG 8 | ND2-COI | DG 8F | AGCAGCCACAATCATGGC |
DG 8R | ATAGATTTGGTCATCTCC |
By comparing and identifying the DNA sequence of each mitochondrial gene in other pigeon families, the range and location of T. curvirostra’s mitochondrial genes were annotated. Hence, the complete mitochondrial genome sequence was used to predict the transcriptional direction of each gene component using the Improved de novo Metazoan Mitochondrial Genome Annotation (MITOS) platform (
We used a concatenated set of base sequences of the 13 PCGs from 34 pigeons and doves to investigate the phylogenetic position of T. curvirostra (Table
Family | Subfamily | Genus | Species | Accession |
---|---|---|---|---|
Columbidae | Columbinae | Geopelia | Geopelia cuneata | MN930521.1 |
Geopelia striata | MG590276.1 | |||
Trugon | Trugon terrestris | MG590263.1 | ||
Caloenas | Caloenas maculata | KX902249.1 | ||
Caloenas nicobarica | MG590264.1 | |||
Streptopelia | Streptopelia tranquebarica | MT535858 | ||
Streptopelia orientalis | KY827037.1 | |||
Streptopelia decaocto | KY827036.1 | |||
Streptopelia chinensis | KP273832.1 | |||
Columba | Columba hodgsonii | MN919176.1 | ||
Columba janthina | LC541479.1 | |||
Columba jouyi | KX902247.1 | |||
Columba livia | KP319029.1 | |||
Columba rupestris | KX902246.1 | |||
Ectopistes | Ectopistes migratorius | KC489473.1 | ||
Patagioenas | Patagioenas fasciata | KX902240.1 | ||
Leptotila | Leptotila verreauxi | HM640214.1 | ||
Zenaida | Zenaida macroura | KX902235.1 | ||
Zenaida auriculata | HM640211.1 | |||
Geotrygon | Geotrygon violacea | HM640213.1 | ||
Turtur | Turtur tympanistria | HM746793.1 | ||
Columbina | Columbina picui | MN356335.1 | ||
Chalcophaps | Chalcophaps indica | HM746789.1 | ||
Treroninae | Alopecoenas | Alopecoenas salamonis | KX902250.1 | |
Hemiphaga | Hemiphaga novaeseelandiae | EU725864.1 | ||
Gourinae | Goura | Goura cristata | MG590273.1 | |
Goura sclaterii | MG590285.1 | |||
Goura scheepmakeri | MG590282.1 | |||
Goura victoria | MG590299.1 | |||
Pezophaps | Pezophaps solitaria | KX902238.1 | ||
Raphus | Raphus cucullatus | KX902236.1 | ||
Otidiphabinae | Otidiphaps | Otidiphaps nobilis | MG590265.1 | |
Didunculinae | Didunculus | Didunculus strigirostris | MG590266.1 | |
Pteroclidae | Pterocles | Pterocles gutturalis | MN356147.1 |
The best substitution models for Bayesian inference (BI) and maximum-likelihood (ML) analyses.
ND1 | ND2 | COI | COII | ATP6 | ATP8 | COIII | ND3 | ND4L | ND4 | ND5 | Cyt b | ND6 | ||
BI | Codon 1 | SYM + I + G4 | GTR + F + I + G4 | SYM + I + G4 | SYM + I + G4 | GTR + F + I + G4 | GTR + F + G4 | SYM + I + G4 | SYM + I + G4 | GTR + F + I + G4 | GTR + F + I + G4 | GTR + F + I + G4 | SYM + I + G4 | GTR + F + G4 |
Codon 2 | GTR + F + I + G4 | GTR + F + I + G4 | GTR + F + I + G4 | GTR + F + I + G4 | GTR + F + I + G4 | GTR + F + I + G4 | GTR + F + I + G4 | GTR + F + I + G4 | GTR + F + I + G4 | GTR + F + I + G4 | GTR + F + I + G4 | GTR + F + I + G4 | HKY + F + I + G4 | |
Codon 3 | GTR + F + I + G4 | GTR + F + I + G4 | GTR + F + I + G4 | GTR + F + I + G4 | GTR + F + I + G4 | GTR + F + I + G4 | GTR + F + I + G4 | GTR + F + I + G4 | GTR + F + I + G4 | GTR + F + I + G4 | GTR + F + I + G4 | GTR + F + I + G4 | GTR + F + G4 | |
ML | TVM + F + R4 | TVM + F + R4 | TIM2 + F + I + G4 | TIM2 + F + I + G4 | TVM + F + R4 | TN + F + I + G4 | TIM2 + F + I + G4 | TIM2 + F + I + G4 | TIM2 + F + I + G4 | TVM + F + R4 | TVM + F + R4 | TIM2 + F + I + G4 | TIM2 + F + I + G4 |
The mitochondrial genome of the Thick-billed Green-Pigeon was found to be 17,414 bp in length, which agrees with the length of most of the other sequenced species of pigeons and doves (Table
Gene | Strand | Position | Anticodon | Size (bp) | Start codon | Intergenic length | |
tRNA-Phe | H | 1–68 | GAA | 68 | 0 | ||
12S rRNA | H | 69–1041 | 973 | 0 | |||
tRNA-Val | H | 1042–1114 | UAC | 73 | 0 | ||
16S rRNA | H | 1115–2703 | 1589 | 0 | |||
tRNA-Leu | H | 2704–2777 | UAA | 74 | 12 | ||
ND1 | H | 2790–3755 | 966 | ATG | AGA | 17 | |
tRNA-Ile | H | 3773–3844 | GAU | 72 | 5 | ||
tRNA-Gln | L | 3850–3920 | UUG | 71 | 0 | ||
tRNA-Met | H | 3921–3988 | CAU | 68 | 0 | ||
ND2 | H | 3989–5027 | 1039 | ATG | T | 0 | |
tRNA-Trp | H | 5028–5098 | UCA | 71 | 1 | ||
tRNA-Ala | L | 5100–5168 | UGC | 69 | 2 | ||
tRNA-Asn | L | 5171–5243 | GUU | 73 | 2 | ||
tRNA-Cys | L | 5246–5313 | GCA | 68 | 0 | ||
tRNA-Tyr | L | 5314–5384 | GUA | 71 | 1 | ||
COI | H | 5386–6936 | 1551 | ATG | AGG | 0 | |
tRNA-Ser | L | 6937–7001 | UGA | 65 | 2 | ||
tRNA-Asp | H | 7004–7072 | GUC | 69 | 1 | ||
COII | H | 7074–7757 | 684 | ATG | TAA | 1 | |
tRNA-Lys | H | 7759–7828 | UUU | 70 | 1 | ||
ATP8 | H | 7830–7997 | 168 | ATG | TAA | 0 | |
ATP6 | H | 7988–8671 | 684 | ATG | TAA | -1 | |
COIII | H | 8671–9454 | 784 | ATG | T | 0 | |
tRNA-Gly | H | 9455–9523 | UCC | 69 | 0 | ||
ND3 | H | 9524–9875 | 352 | ATT | TAA | 1 | |
tRNA-Arg | H | 9877–9945 | UCG | 69 | 1 | ||
ND4L | H | 9947–10243 | 297 | ATG | TAA | -7 | |
ND4 | H | 10237–11614 | 1378 | ATG | T | 0 | |
tRNA-His | H | 11615–11683 | GUG | 69 | 0 | ||
tRNA-Ser | H | 11684–11749 | GCU | 66 | 0 | ||
tRNA-Leu | H | 11750–11819 | UAG | 70 | 0 | ||
ND5 | H | 11820–13637 | 1818 | ATG | AGA | 8 | |
Cyt b | H | 13646–14788 | 1143 | ATG | TAA | 0 | |
tRNA-Thr | H | 14789–14856 | UGU | 68 | 6 | ||
tRNA-Pro | L | 14863–14932 | UGG | 70 | 4 | ||
ND6 | L | 14937–15458 | 522 | ATG | TAG | 3 | |
tRNA-Glu | L | 15462–15532 | UUC | 71 | 0 | ||
D-loop | 15553–17414 | 1862 | 0 |
The total length of the PCGs was 11,386 bp, which is consistent with the average length of PCGs found in Columbidae (Table
Region | A% | T% | AT-skew | G% | C% | GC-skew |
---|---|---|---|---|---|---|
whole mitogenome | 30.32 | 24.83 | 0.100 | 13.61 | 31.24 | -0.393 |
PCGs | 29.46 | 24.56 | 0.091 | 12.23 | 33.76 | -0.468 |
rRNAs | 32.75 | 21.19 | 0.214 | 19.05 | 27.01 | -0.173 |
tRNAs | 32.33 | 25.16 | 0.125 | 16.95 | 25.55 | -0.203 |
D-loop | 30.45 | 31.31 | -0.014 | 11.92 | 26.32 | -0.376 |
Nucleotide composition indices in different regions of mitogenomes of Columbidae.
Species | GenBank no | Whole mitogenome | Protein coding genes | Ribosomal RNA | |||
---|---|---|---|---|---|---|---|
Length (bp) | AT (%) | Length (bp) | AT (%) | Length (bp) | AT (%) | ||
Goura sclaterii | MG590285.1 | 18242 | 54.13 | 11386 | 52.99 | 2571 | 53.21 |
Treron curvirostra | MT535857 | 17414 | 55.16 | 11386 | 54.02 | 2562 | 53.94 |
Columba hodgsonii | MN919176.1 | 17477 | 54.55 | 11385 | 53.82 | 2557 | 53.23 |
Trugon terrestris | MG590263.1 | 17405 | 55.62 | 11395 | 54.94 | 2569 | 55.86 |
Didunculus strigirostris | MG590266.1 | 17389 | 54.94 | 11390 | 54.32 | 2569 | 55 |
Geopelia striata | MG590276.1 | 17354 | 54.83 | 11383 | 53.78 | 2565 | 54.07 |
Otidiphaps nobilis | MG590265.1 | 17346 | 55.83 | 11382 | 55.2 | 2581 | 54.75 |
Hemiphaga novaeseelandiae | EU725864.1 | 17264 | 54.89 | 11386 | 54.1 | 2575 | 54.52 |
Caloenas nicobarica | MG590264.1 | 17178 | 55.13 | 11386 | 54.83 | 2567 | 53.64 |
Leptotila verreauxi | HM640214.1 | 17176 | 54.1 | 11383 | 53.34 | 2556 | 53.4 |
Alopecoenas salamonis | KX902250.1 | 17141 | 55.18 | 11381 | 54.78 | 2569 | 54.81 |
Streptopelia orientalis | KY827037.1 | 17102 | 53.41 | 11386 | 52.86 | 2561 | 53.58 |
Raphus cucullatus | KX902236.1 | 17092 | 56.08 | 11385 | 55.87 | 2566 | 54.6 |
Ectopistes migratorius | KC489473.1 | 17026 | 54.52 | 11383 | 54.3 | 2596 | 52.97 |
Patagioenas fasciata | KX902239.1 | 16970 | 54.51 | 11384 | 54.02 | 2550 | 53.8 |
Geotrygon violacea | HM640213.1 | 16864 | 55.04 | 11383 | 54.27 | 2561 | 53.85 |
Zenaida auriculata | HM640211.1 | 16781 | 53.29 | 11380 | 52.71 | 2567 | 52.83 |
The mitogenome of T. curvirostra contained 22 tRNAs with lengths ranging from 65 bp (tRNA-Ser (UGA)) to 74 bp (tRNA-Leu (UAA)), which is similar to that in the mitogenomes of other pigeons and doves (
The total size of the two rRNAs was 2,562 bp, with an A+T content of 53.94%, an AT-skew of 0.2142, and a GC-skew of -0.1729 (Table
A D-loop was found between tRNA-Glu and tRNA-Phe, and was 1,862 bp in length, with a A+T content of 61.76%, an AT-skew of -0.0139, and a GC-skew of -0.3764 (Table
Although the topology of ML tree and BI tree were similar to each other, they differed with respect to the phylogenetic position of T. curvirostra. Treron curvirostra clustered with Hemiphaga novaeseelandiae (Gmelin, 1789) in the BI tree, whereas it did not cluster with any species in the ML tree (Fig.
The authors declare no competing interest exists. This study was supported by the National Natural Science Foundation of China (No. 31800453), the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD), and the Innovation and Entrepreneurship Training Program for College Students of China (202010298035Z).