Mitochondrial DNA (mtDNA)

In the avian ground pattern, the mitochondrial genome (mitogenome) consists of 2 rRNA genes, 22 tRNA genes, 13 protein-coding genes, a control region, and (putatively) a tandem duplication: 

Circular map depicting the putative ancestral avian mitogenome organisation (not to scale). The tandem duplication (TD), which extends between CR and F, is shown separately. When fully developed, it contains a pseudogene Ψ (considered a degenerate partial copy of CYB), four functional genes, and an extended control region (Urantówka et al., 2020). 

The 22 tRNA-genes are short, ranging from 64 to 78 base pairs (bp). Since tRNAs play an important role in translating mRNA into protein, they are rather conserved. 

The 13 protein-coding genes are much longer and exhibit a higher rate of nucleotide substitution. For decades, some of these genes (CO1, CYB, ND2) have routinely been used in phylogenetic studies. While individual gene trees derived from the protein-coding genes and control region usually differ from each other and from species trees based on nuclear DNA, phylogenies that are based on entire mitogenomes are mostly concordant with nuclear DNA-based species trees. Because of the observed gene-tree discordance between individual mtDNA genes, phylogenetic studies should no longer rely on limited sets of mitochondrial genes but on the mitogenome as a whole (Meiklejohn et al., 2014; Campillo et al., 2019). Since protein-coding mtDNA has a higher mutation rate than nuclear DNA, mitochondrial genes are particularly suitable for studying shallow (intra- and interspecific) phylogenetic relationships. 

The protein-coding gene ND3 is peculiar in having an extra nucleotide (mostly cytosine) at position 174. Its presence probably pertains to the avian ground pattern, but it has been lost several times during avian evolution. The extra base, however, appears not to be processed during translation, as the downstream reading frame and amino-acid sequence are conserved (Mindell et al., 1998b). 


Summary of avian mitochondrial annotations. Duplicated regions are not considered. In protein-coding genes, partial stop codons (TA and T) serve as stop signals after they are completed to UAA by posttranscriptional polyadenylation. 


Tandem duplication

Avian mitogenomes are distinguished from typical vertebrate mitogenomes by the presence of an additional tandem duplication (Urantówka et al., 2018, 2020, 2021; Mackiewicz et al., 2019). Dating back to Haring et al. (1999), this region is sometimes referred to “pseudo-control region”. With the exception of the duplicated control region (CR2), which is slightly different from CR1, duplicated genes are often identical to their counterpart, a phenomenon referred to as “concerted evolution” (Urantówka et al., 2021). However, numerous deviations from the original configuration are observed among and within avian orders. Tandem duplications seem to be entirely absent in Galloanserae. 

COI barcoding

DNA barcoding is a method of species identification by comparing DNA sequences of an unknown sample with DNA sequences of known species via public online reference databases. In animals, the sequence used for DNA barcoding is a 648-bp fragment of the mitochondrial CO1 gene. The length of the fragment is determined by the limits of Sanger sequencing. 

COI-barcoding has been chosen, because it turned out that most animal species (except cnidarians) are separated from congeneric species by CO1 sequence divergences higher than 2%, while sequence divergences among conspecifics are usually less than 2% (Hebert et al., 2003). This observation is referred to as the “barcode gap” (Meyer & Paulay, 2005). More than 94% of morphologically defined bird species have been confirmed with COI as a species-level marker gene (Wang et al., 2020). 

In a comparative avian mitogenomic study, the CO1 gene proved to be the one with the least amount of rate heterogeneity across avian orders, thus being closest to a “molecular clock” (Pacheco et al., 2011). This explains its suitability as an indicator of species limits. 

References/Literature

Abbott CL, Double MC, Trueman JWH, Robinson A, and Cockburn A (2005), An unusual source of apparent mitochondrial heteroplasmy: duplicate mitochondrial control regions in Thalassarche albatrosses, Mol. Ecol. 14, 3605-13. (abstract)

Adawaren EO, Du Plessis M, Suleman E, Kindler D, Oosthuizen AO, Mukandiwa L, and Naidoo V (2020), The complete mitochondrial genome of Gyps coprotheres (Aves, Accipitridae, Accipitriformes): phylogenetic analysis of mitogenome among raptors, PeerJ 8, e:10034. (pdf)

Al-Arab M, Höner zu Siederdissen C, Tout K, and Sahyoun AH (2017), Accurate annotation of protein-coding genes in mitochondrial genomes, Mol. Phylogenet. Evol. 106, 209-216. (abstract)

Anmarkrud JA, and Lifjeld JT (2017), Complete mitochondrial genomes of eleven extinct or possibly extinct bird species, Mol. Ecol. Res. 17, 334-341. (abstract)

Baker AJ, and Marshall HD (1997), Mitochondrial control-region sequences as tools for understanding the evolution of avian taxa, In: “Avian molecular systematics and evolution” (Mindell DP, ed.), pp. 49-80, Academic Press, NY. (link)

Barreira AS, Lijtmaer DA, and Tubaro PL (2016), The multiple applications of DNA barcodes in avian evolutionary studies, Genome 59, 899-911. (free pdf)

Bensch S, and Härlid A (2000), Mitochondrial genomic rearrangements in songbirds, Mol. Biol. Evol. 17, 107-113. (free pdf)

Bi D, Ding H, Wang Q, Jiang L, Lu W, Zhu R, Zeng J, Zhou S, Yang X, and Kan X (2019), Two new mitogenomes of Picidae (Aves, Piciformes): sequence, structure and phylogenetic analyses, Int. J. Biol. Macromol. 133, 683-692. (abstract)

Buehler DM, and Baker AJ (2003), Characterization of the red knot (Calidris canutus) mitochondrial control region, Genome 46, 565-572. (abstract)

Campillo LC, Burns KJ, Moyle RG, and Manthey JD (2019), Mitochondrial genomes of the bird genus Piranga: rates of sequence evolution, and discordance between mitochondrial and nuclear markers, Mitochondrial DNA B 4, 2566-69. (free pdf)

Caparroz R, Rocha AV, Cabanne GS, Tubaro P, Aleixo A, Lemmon EM, and Lemmon AR (2018), Mitogenomes of two neotropical bird species and the multiple independent origin of mitochondrial gene orders in Passeriformes, Mol. Biol. Rep. 45, 279-285. (abstract)

Chen DS, Qian CJ, Ren QQ, Wang P, Yuan J, Jiang L, Bi D, Zhang Q, Wang Y, and Kan XZ (2015), Complete mitochondrial genome of the Chinese Hwamei Garrulax canorus (Aves: Passeriformes): the first representative of the Leiotrichidae family with a duplicated control region, Genet. Mol. Res. 14, 8964-76. (pdf)

Chen P, Han Y, Zhu C, Gao B, and Ruan L (2017), Complete mitochondrial genome of Porzana fusca and Porzana pusilla and phylogenetic relationship of 16 Rallidae species, Genetica 145, 559-573. (abstract)

Cho HJ, Eda M, Nishida S, Yasukochi Y, Chong JR, and Koike H (2009), Tandem duplication of mitochondrial DNA in the black-faced spoonbill, Platalea minor, Genes Genet. Syst. 84, 297-305. (pdf)

Colihueque N, Gants A, and Parraguez M (2021), Revealing the diversity of Chilean birds through the COI barcode approach, ZooKeys 1016, 143-161. (free pdf)

Crochet PA, and Desmarais E (2000), Slow rate of evolution of the mitochondrial control region of gulls (Aves: Laridae), Mol. Biol. Evol. 17, 1797-806. (free pdf)

Del-Rio G, Rego MA, Whitney BM, Schunck F, Silveira LF, Faircloth BC, and Brumfield RT (2021), Displaced clines in an avian hybrid zone (Thamnophilidae: Rhegmatorhina) within an Amazonian Interfluve, Evolution (abstract)

De Panis D, Lambertucci SA, Wiemeyer G, Dopazo H, Almeida FC, Mazzoni CJ, Gut M, Gut I, and Padró J (2021), Mitogenomic analysis of extant condor species provides insight into the molecular evolution of vultures, Sci. Rep. 11, e:17109. (pdf)

Desjardins P, and Morais R (1999), Sequence and gene organization of the chicken mitochondrial genome: a novel gene order in higher vertebrates, J. Mol. Biol. 212, 599-634. (abstract)

Dey P, Sharma SK, Sarkar I, Ray SD, Pramod P, Kochiganti VHS, Quadros G, Rathore SS, Singh V, and Singh RP (2021), Complete mitogenome of endemic plum-headed parakeet Psittacula cyanocephala – characterization and phylogenetic analysis, PLOS ONE 16, e:0241098. (free pdf)

Dey P, Sarkar I, Ray SD, Pramod P, Natarajan J, and Singh RP (2022), Genome survey sequencing, microsatellite motif identification and complete mitogenome of Turnix suscitator – novel implications for Charadriiformes phylogeny, Helyon (pdf)

Dias C, de Araújo Lima K, Araripe J, Aleixo A, Vallinoto M, Sampaio I, Schneider H, and Sena do Rêgo P (2018), Mitochondrial introgression obscures phylogenetic relationships among manakins of the genus Lepidothrix (Aves: Pipridae), MolPhylogenetEvol. 126, 314-320. (abstract)

Du C, Liu Y, and Fu Z (2020), The complete mitochondrial genome of the Eurasian wryneck Jynx torquilla (Aves: Piciformes: Picidae) and its phylogenetic inference, Zootaxa 4810, 351-360. (abstract)

Eberhard JR, and Wright TF (2016), Rearrangement and evolution of mitochondrial genomes in parrots, Mol. Phylogenet. Evol. 94, 34-46. (abstract) 

Eberhard JR, Wright TF, and Bermingham E (2001), Duplication and concerted evolution of the mitochondrial control region in the parrot genus Amazona, Mol. Biol. Evol. 18, 1330-1342. (free pdf) 

Formenti G, Rhie A, Balacco J, Haase B, Mountcastle J, Fedrigo O, Brown S, Capodiferro MR, Al-Ajli FO, Ambrosini R, Houde P, Koren S, Oliver K, Smith M, Skelton J, Betteridge E, Dolucan J, Corton C, Bista I, Torrance J, Tracey A, Wood J, Uliano-Silva M, Howe K, McCarthy S, Winkler S, Kwak W, Korlach J, Fungtammasan A, Fordham D, Costa V, Mayes S, Chiara M, Horner DS, Myers E, Durbin R, Achilli A, Braun EL, Phillippy AM, and Jarvis ED (2021), Complete vertebrate mitogenomes reveal widespread repeats and gene duplications, Genome Biol. 22, e:120. (pdf)

Gong J, Zhao R, Huang Q, Sun X, Huang L, and Jing M (2017), Two mitogenomes of Gruiformes (Amaurornis akool/A. phoenicurus) and the phylogenetic placement of Rallidae, Genes Genom. 39, 987-995. (abstract)

Härlid A, Janke A, and Arnason U (1998), The complete mitochondrial genome of Rhea americana and early avian divergences, J. Mol. Evol. 46, 669-679. (abstract)

Hanna ZR, Henderson JB, Sellas AB, Fuchs J, Bowie RCK, and Dumbacher JP (2017), Complete mitochondrial genome sequences of the northern spotted owl (Strix occidentalis caurina) and the barred owl (Strix varia; Aves: Strigiformes: Strigidae) confirm the presence of a duplicated control region, PeerJ 5, e:3901. (pdf)

Harrison GL, McLenachan PA, Phillips MJ, Slack KE, Cooper A, and Penny D (2004), Four new avian mitochondrial genomes help get to basic evolutionary questions in the Late Cretaceous, Mol. Biol. Evol. 21, 974-983. (free pdf)

Hebert PDN, Ratnasingham S, and deWaard JR (2003), Barcoding animal life: cytochrome c oxidase subunit 1 divergences among closely related species, Proc. R. Soc. Lond. B (Suppl.) 270, S96-99. (pdf)

Hebert PDN, Stoeckle MY, Zemlak TS, and Francis CM (2004), Identification of birds through DNA barcodes, PLoS Biol. 2, 1657-63. (pdf) 

Huang Z, Tu F, and Murphy RW (2016), Analysis of the complete mitogenome of Oriental turtle dove (Streptopelia orientalis) and implications for species divergence, Biochem. Syst. Ecol. 65, 209-213. (abstract)

Huang Z, Tu F, and Tang S (2018), Two new mitogenomes of Pellorneidae (Aves: Passeriformes) and a phylogeny of the superfamily Sylvioidea, Austr. J. Zool. 66, 167-173. (abstract)

Jiang L, Chen J, Wang P, Ren Q, Yuan J, Qian C, Hua X, Guo Z, Zhang L, Yang J, Wang Y, Zhang Q, Ding H, Bi D, Zhang Z, Wang Q, Chen D, and Kan X (2015), The mitochondrial genomes of Aquila fasciata and Buteo lagopus (Aves, Accipitriformes): sequence, structure and phylogenetic analyses, PLoS ONE 10, e:0136297. (pdf)

Jiang L, Peng L, Tang M, You Z, Zhang M, West A, Ruan Q, Chen W, and Merilä J (2019), Complete mitochondrial genome sequence of the Himalayan Griffon, Gyps himalayensis (Accipitriformes: Accipitridae): sequence, structure, and phylogenetic analyses, Ecol. Evol. 9, 8813-28. (pdf)

Jing M, Yang H, Li K, and Huang L (2020), Characterization of three new mitochondrial genomes of Coraciiformes (Megaceryle lugubris, Alcedo atthis, Halcyon smyrnensis) and insights into their phylogenetics, Genet. Mol. Biol. 43, e:20190392. (abstract)

Johnsen A, Kearns AM, Omland KE, and Anmarkrud JA (2017), Sequencing of the complete mitochondrial genome of the common raven Corvus corax (Aves: Corvidae) confirms mitogenome-wide deep lineages and a paraphyletic relationship with the Chihuahuan raven C. cryptoleucus, PLoS ONE 12, e:0187316. (pdf)

Kan XZ, Li XF, Lei ZP, Wang M, Chen L, Gao H, and Yang ZY (2010a), Complete mitochondrial genome of Cabot‘s tragopan, Tragopan caboti (Galliformes: Phasianidae), Genet. Mol. Res. 9, 1204-1216. (pdf)

Kan XZ, Li XF, Zhang LQ, Chen L, Qian CJ, Zhang XW, and Wang L (2010b), Characterization of the complete mitochondrial genome of the rock pigeon, Columba livia (Columbiformes, Columbidae), Genet. Mol. Res. 9, 1234-49. (pdf)

Kundu S, Alam I, Maheswaran G, Tyagi K, and Kumar (2021), Complete mitochondrial genome of Great Frigatebird (Fregata minor): phylogenetic position and gene rearrangement, Biochem. Genet. (abstract)

Kuro-o M, Yonekawa H, Saito S, Eda M, Higuchi H, Koike H, and Hasegawa H (2010), Unexpectedly high genetic diversity of mtDNA control region through severe bottleneck in vulnerable albatross Phoebastria albatrus, Conserv. Genet. 11, 127-137. (abstract)

Lai WN, Yan SQ, Jiao SY, Yao JY, and Li YM (2019), Complete mitochondrial genome of Dendrocopos canicapillus (Piciformes: Picidae), Mitochondrial DNA B 4, 141-142. (abstract)

Liu G, Li C, Du Y, and Liu X (2017), The complete mitochondrial genome of Japanese sparrowhawk (Accipiter gularis) and the phylogenetic relationships among some predatory birds, Biochem. Syst. Ecol. 70, 116-125. (abstract)

Mackiewicz P, Urantówka AD, Kroczak A, and Mackiewicz D (2019), Resolving phylogenetic relationships within Passeriformes based on mitochondrial genes and inferring the evolution of their mitogenomes in terms of duplications, Genome BiolEvol. 11, 2824-49. (free pdf)

Meiklejohn KA, Danielson MJ, Faircloth BC, Glenn TC, Braun EL, and Kimball RT (2014), Incongruence among different mitochondrial regions: a case study using complete mitogenomes, Mol. Phylogenet. Evol. 78, 314-323. (abstract)

Meyer CP, and Paulay G (2005), DNA barcoding: error rates based on comprehensive sampling, PLoS Biol. 3, e:422. (pdf)

Mindell DP, Sorenson MD, and Dimcheff DE (1998a), Multiple independent origins of mitochondrial gene order in birds, Proc. Natl. Acad. Sci. USA 95, 10693-97. (pdf)

Mindell DP, Sorenson MD, and Dimcheff DE (1998b), An extra nucleotide is not translated in mitochondrial ND3 of some birds and turtles, Mol. Biol. Evol. 15, 1568-71. (free pdf)

Mindell DP, Sorenson MD, Dimcheff DE, Hasegawa M, Ast JC, and Yuri (1999), Interordinal relationships of birds and other reptiles based on whole mitochondrial genomes, Syst. Biol. 48, 138-152. (free pdf)

Mitchell KJ, Wood JR, Scofield RP, Llamas B, and Cooper A (2013), Ancient mitochondrial genome reveals unsuspected taxonomic affinity of the extinct Chatham duck (Pachyanas chathamica) and resolves divergence times for New Zealand and sub-Antarctic brown teals, Mol. Phylogenet. Evol. 70, 420-428. (abstract)

Morgan-Richards M, Bulgarella M, Sivyer L, Dowle EJ, Hale M, McKean NE, and Trewick SA (2017), Explaining large mitochondrial sequence differences within a population sample, R. Socopen sci. 4, e:170730. (pdf)

Morris-Pocock JA, Taylor SA, Birt TP, and Friesen VL (2010), Concerted evolution of duplicated mitochondrial control regions in three related seabird species, BMC Evol. Biol. 10, e:14. (pdf)

Nabholz B, Jarvis E, and Ellegren H (2010), Obtaining mtDNA genomes from next-generation transcriptome sequencing: a case study on the basal Passerida (Aves: Passeriformes) phylogeny, Mol. Phylogenet. Evol. 57, 466-470. (abstract)

Pacheco MA, Battistuzzi FU, Lentino M, Aguilar RF, Kumar S, and Escalante AA (2011), Evolution of modern birds revealed by mitogenomics: timing the radiation and origin of major orders, Mol. Biol. Evol. 28, 1927-42. (free pdf)

Peng C, Li J, Lu H, Liu W, and Zhang J (2022), Characterization of the complete mitochondrial genome of the Sea Duck Mergus serrator and comparison with other Anseriformes species, Res. Square (pdf)

Ramirez V, Savoie P, and Morais R (1993), Molecular characterization and evolution of a duck mitochondrial genome, J. Mol. Evol. 37, 296-310. (abstract)

Randi E, and Lucchini V (1998), Organization and evolution of the mitochondrial DNA control region in the avian genus Alectoris, J. Mol. Evol. 47, 449-462. (abstract)

Ratnasingham S, and Hebert PDN (2013), A DNA-based registry for all animal species: the Barcode Index Number (BIN) system, PLOS ONE 8, e:66213. (pdf)

Ren Q, Qian C, Yuan J, Li X, Yang J, Wang P, Jiang L, Zhang Q, Wang Y, and Kan X (2014), Complete mitochondrial genome of the Black-capped Bulbul, Pycnonotus melanicterus (Passeriformes: Pycnonotidae), Mitochondrial DNA A 27, 1378-80. (abstract)

Roques S, Godoy A, Negro JJ, and Hiraldo F (2004), Organization and variation of the mitochondrial control region in two vulture species, Gypaetus barbatus and Neophron percnopterus, J. Hered. 95, 332-337. (free pdf)

Ruokonen M, and Kvist L (2002), Structure and evolution of the avian mitochondrial control region, Mol. Phylogenet. Evol. 23, 422-432. (abstract)

Sammler S, Bleidorn C, and Tiedemann R (2011), Full mitochondrial genome sequences of two endemic Philippine hornbill species (Aves: Bucerotidae) provide evidence for pervasive mitochondrial DNA recombination, BMC Genomics 12, e:35. (pdf)

Sarkar I, Dey P, Sharma SK, Ray SD, Kochiganti VHS, Singh R, Pramod P, and Singh RP (2020), Turdoides affinis mitogenome reveals the translational efficiency and importance of NADH dehydrogenase complex-I in the Leiotrichidae family, Sci. Rep. 10, e:16202. (pdf)

Singh TR, Shneor O, and Huchon D (2008), Bird mitochondrial gene order: insight from 3 warbler mitochondrial genomes,  Mol. Biol. Evol. 25, 475-477. (free pdf)

Sloan DB, Havird JC, and Sharbrough J (2016), The on-again, off-again relationship between mitochondrial genomes and species boundaries, Mol. Ecol. 26, 2212-36. (pdf)

Sun CH, Liu HY, Min X and Lu CH (2020), Mitogenome of the little owl Athene noctua and phylogenetic analysis of Strigidae, Int. J. Biol. Macromol. 151, 924-931. (abstract)

Urantówka AD, Kroczak A, Silva T, Padrón RZ, Gallardo NF, Blanch J, Blanch B, and Mackiewicz P (2018), New insight into parrot’s mitogenomes indicates that their ancestor contained a duplicated region, MolBiolEvol. 35, 2989-3008. (free pdf)

Urantówka AD, Kroczak A, and Mackiewicz P (2020), New view on the organization and evolution of Palaeognathae mitogenomes poses the question on the ancestral rearrangement in Aves, BMC Genomics 21, e:874. (pdf)

Urantówka AD, Kroczak A, Strzala T, Zaniewicz G, Kurkowski M, and Mackiewicz P (2021), Mitogenomes of Accipitriformes and Cathartiformes were subjected to ancestral and recent duplications followed by gradual degradation, Genome BiolEvol. 13, e:evab193. (pdf) 

Wang E, Zhang D, Braun MS, Hotz-Wagenblatt A, Pärt T, Arlt D, Schmaljohann H, Bairlein F, Lei F, and Wink M (2020), Can mitogenomes of the Northern Wheatear (Oenanthe oenanthe) reconstruct its phylogeography and reveal the origin of migrant birds?, Sci. Rep. 10, e:9290. (pdf)

Wang J, Liu G, Zhou L, Quing H, Li L, Li B, and Zhang L (2014), Complete mitochondrial genome of Tundra swan Cygnus columbianus jankowskii (Anseriformes: Anatidae), Mitochondrial DNA 27, 90-91. (abstract)

Watanabe M, Nikaido M, Tsuda TT, Kobayashi T, Mindell D, Cao Y, Okada N, and Hasegawa M (2006), New candidate species most closely related to penguins, Gene 378, 65-73. (abstract)

Xu N, Ding J, Que Z, Xu W, Ye W, and 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. (pdf) 

Yamamoto Y, Murata K, Matsuda H, Hosoda T, Tamura K, and Furuyama JI (2000), Determination of the complete nucleotide sequence and haplotypes in the D-loop region of the mitochondrial genome in the oriental white stork, Ciconia boyciana, Genes Genet. Syst. 75, 25-32. (pdf)

Yan C, Mou B, Meng Y, Tu F, Fan Z, Price M, Yue B, and Zhang X (2017), A novel mitochondrial genome of Arborophila and new insight into Arborophila evolutionary history, PLoS ONE 12, e:0181649. (pdf)

Yang R, Wu X, Yan P, Su X, and Yang B (2010), Complete mitochondrial genome of Otis tarda (Gruiformes, Otididae) and phylogeny of Gruiformes inferred from mitochondrial DNA sequences, Mol. Biol. Rep. 37, 3057-3066. (abstract)

Yoon BK, Cho CU, and Park YC (2015), The mitochondrial genome of the Saunders’s gull Chroicocephalus saundersi (Charadriiformes: Laridae) and a higher phylogeny of shorebirds (Charadriiformes), Gene 572, 227-236. (abstract)

Yuan QM, Luo X, Cao J, and Duan YB (2021), Complete mitochondrial genomes of three nuthatches from the genus Sitta (Aves: Passeriformes: Sittidae) and mitogenome-based phylogenetic analysis, Res. Square (pdf) 

Zhang H, Bai Y, Shi X, Wang Z, and Wu X (2018), The complete mitochondrial genomes of Tarsiger cyanurus and Phoenicurus auroreus: a phylogenetic analysis of Passeriformes, Genes Genomics 40, 151-165. (abstract)

Zhong Y, Zhou M, Ouyang B, Zeng C, Zhang M, and Yang J (2020), Complete mtDNA genome of Otus sunia (Aves, Strigidae) and the relaxation of selective constrains on Strigiformes mtDNA following evolution, Genomics 112, 3815-25. (pdf) 

Zhou C, Hao Y, Ma J, Zhang W, Chen Y, Chen B, Zhang X, and Yue B (2017), The first complete mitogenome of Picumnus innominatus (Aves, Piciformes, Picidae) and phylogenetic inference within the Picidae, Biochem. Syst. Ecol. 70, 274-282. (abstract)

Zhou X, Lin Q, Fang W, and Chen X (2014), The complete mitochondrial genomes of sixteen ardeid birds revealing the evolutionary process of the gene rearrangements, BMC Genomics 15, e:573. (pdf)

Zou Y, Jing MD, Bi XX, Zhang T, and Huang L (2015), The complete mitochondrial genome sequence of the little egret (Egretta garzeta), Genet. Mol. Biol. 38, 162-172. (pdf)