Pseudo-control Region Research Articles

Contrasting patterns of genetic diversity and lack of population structure in the lesser spotted eagleClanga pomarina(Aves: Accipitriformes) across its breeding range

AbstractCharacterizing the genetic diversity and structure of populations is essential for understanding their evolutionary history and planning species conservation. The lesser spotted eagle (Clanga pomarina) is a large migratory raptor with a relatively small breeding range concentrated in Eastern Europe. We evaluated the level of genetic diversity and population structuring by estimating the length diversity of 23 microsatellite markers in 306 individuals and sequencing 473 nucleotides from the mitochondrial pseudo-control region in 265 individuals across the distribution range. The microsatellite data suggested shallow differentiation between geographical regions and moderate genetic diversity across the range; no recent population bottlenecks were detected. Mitochondrial diversity was relatively low; however, high values were recorded at the southern edge of the distribution range. This, in combination with the star-like distribution of mitochondrial haplotypes, suggests the expansion of the European population from a single (Balkan) refugium during the late Pleistocene or early Holocene after the glacial population bottleneck. However, the Caucasian population may have survived in a separate refugium. We conclude that the lack of clear population structuring and ongoing gene flow across Europe support the treatment of the geographically restricted global population of the lesser spotted eagle as a single evolutionary and conservation unit.

Characterization of the complete mitochondrial genome of Elanus caeruleus Desfontaines, 1789 (Accipitriformes: Accipitridae)

The complete mitochondrial genome of the Elanus caeruleus was sequenced via next-generation sequencing. The circular mitogenome is 18,898 bp in length, containing 13 protein-coding genes, 22 transfer RNA genes, 2 ribosomal RNA genes, a control region and a pseudo control region. The sequences (1210 bp) in the middle part of the two control regions are complete identical to each other. The gene order of the E. caeruleus mitogenome is identical to those of other Accipitridae species. The phylogenetic analysis indicated that E. caeruleus formed a basal lineage sister to other species within the Accipitridae family.

Complete mitochondrial genome of the spectacled parrotbill Sinosuthora conspicillata David, 1871 (Aves: Passeriformes: Sylviidae)

The mitochondrial genome of the spectacled parrotbill Sinosuthora conspicillata is sequenced by the Sanger method. The genome is 16,982 bp in length, comprising of 13 protein-coding genes (PCGs), 2 rRNA genes, 22 tRNA genes, 1 control region (D-loop), and 1 pseudo-control region. The PCGs of COX1 and ND3 use GTG and ATA as their starting codon, respectively, while all other PCGs start with ATG codons. Four PCGs (COX3, ND4, ND5, and ND6) are terminated with CCT, TAT, AGA, and TAG, respectively, and all other PCGs end with TAA. The 22 tRNAs range from 66 bp (tRNA-Ser) to 75 bp (tRNA-Leu) in length. The two rRNAs are 984 bp (12S) and 1600 bp (16S) in length. Phylogenetic analysis indicated that S. conspicillata is closely related to the congeneric vinous-throated parrotbill S. webbiana. This mitochondrial genome sequence offers a valuable resource for future conservation genetic and phylogenetic studies of birds in the family Sylviidae (Passeriformes).

The complete mitochondrial genome of Eurasian Sparrowhawk Accipiter nisus (Accipitriformes: Accipitridae)

The mitogenome of the Accipiter nisus is a circular module of 18,352 bp, which consists of 39 genes, containing 2 rRNA genes (12S rRNA and 16S rRNA), 13 protein-coding genes, 22 tRNA genes, and two non-coding regions (control region and pseudo control region). The mitogenome of A. nisus is composed of 31.3% A, 25.5% T, 30.4% C, 12.8% G, and 76.3% AT. The phylogenetic analysis revealed that A. nisus individuals was well grouped in Accipitridae and more closely related to genus Circus than other Accpiter species

Discovery of a Novel Mtdna Sequence in the Eastern Buzzard (Buteo Japonicus) in Japan

In recent years, several phylogenetic studies on the genus Buteo have been conducted. However, little is known about the lineage of the Eastern Buzzard (Buteo japonicus). We sequenced 919-bp fragments of mtDNA from 45 Eastern Buzzards from Japan and compared them with the sequences of the genus Buteo registered in the DDBJ/EMBL/GenBank databases. ND6 and pseudo control region phylogenetic analyses were performed on 15 and 35 specimens in the database, respectively. All 45 Eastern Buzzards from Japan possessed the same novel sequence in the ND6 gene, which differed in four base pairs from sequences previously reported for the Eastern Buzzard from continental Asia. Phylogenetic analysis of the ND6 gene showed that Japanese birds with the novel sequence did not form a clade with those from continental Asia with the previously reported sequences; instead, the continental Eastern Buzzard formed a clade with Himalayan Buzzards (Buteo refectus). A phylogenetic tree constructed using pseudo control region sequences showed that Eastern Buzzards were divided into two groups: one containing the Himalayan Buzzard, and one containing birds with the novel sequence. Our results suggested that the novel sequence revealed in this study is a geographic variant that may represent the “true” Eastern Buzzard, and that the previously reported sequence (from continental Asia) is that of the Himalayan Buzzard. We suggest that it is necessary to examine the habitats and characteristics of Eastern and Himalayan Buzzards in eastern Eurasia to more accurately classify these birds.

Complete mitochondrial genome and the phylogenetic position of the common cuckoo, Cuculus canorus bakeri (Aves: Cuculiformes)

The complete mitochondrial genome of Common Cuckoo (Cuculus canorus bakeri) is determined in this study and was deposited in Genbank with accession number MN067867. The length of the mitogenome is 17,457 base pairs (bp) including 13 protein-coding genes (PCGs), 22 transfer (t RNA) RNA genes, two ribosomal RNA (r RNA) genes, one control region (CR) and one short pseudo-control region. The structure is similar to mitochondrial genome of other Cuculiforme species. Phylogenetic tree shows that C. canorus bakeri is closely related to C. poliocephalus. The study has provided useful information for further studies on the evolution, genetic diversity, and phylogenetic relationships in Common Cuckoo.

High genetic diversity and low differentiation retained in the European fragmented and declining Greater Spotted Eagle (Clanga clanga) population

Characterising genetic diversity and structure of populations is essential for effective conservation of threatened species. The Greater Spotted Eagle (Clanga clanga), a large and globally vulnerable raptor, is extinct or in severe decline in most of its previous range in Europe. We assessed whether the remnants of European population are genetically impoverished, and isolated from each other. We evaluated levels of genetic diversity and population structuring by sequencing mitochondrial pseudo-control region and 10 introns from various nuclear genes, and estimated length diversity in 23 microsatellite markers. The European population has expanded since the late Pleistocene, and does not exhibit signs of a recent population bottleneck. The global genetic diversity in Europe was rather similar to that detected in other similar species. Microsatellites suggested shallow but significant differentiation between the four extant populations in Estonia, Poland, Belarus and Russia (Upper Volga region) populations, but introns and mtDNA showed that only the Estonian population differed from the others. Mitochondrial diversity was highest in the northernmost Estonian population, introns suggested lower diversity in Upper Volga, microsatellites indicated equal diversity among populations. A recent bottleneck was detected in Poland, which is consistent with the observed repopulation of the region. We conclude that significant gene flow and high genetic diversity are retained in the fragmented Greater Spotted Eagle populations; there is currently no need for genetic augmentation in Europe.

The Complete Mitogenome of Falco amurensis (Falconiformes, Falconidae), and a Comparative Analysis of Genus Falco.

In this study, we sequenced the complete mitogenome of Falco amurensis (Falconiformes, Falconidae). The F. amurensis mitogenome is 17,464 bp long, and contains 37 genes, including 13 protein-coding genes (PCGs), two rRNAs, 22 tRNAs, and two non-coding regions (control region and pseudo-control region). Most PCGs initiate with ATG and terminate with TAA. atp8 exhibits the highest evolutionary rate, with cox1 showing the lowest. rrnS and rrnL contain three domains with 46 helices and six domains with 59 helices, respectively. All tRNAs have a typical cloverleaf secondary structure, except that trnS(agy) lacks the dihydrouracil arm. The control region is located between trnT and trnP and the pseudo-control between trnE and trnF. Phylogenetic relationships of 23 species from Falconiformes were analyzed based on the nucleotide sequences of the 13 PCGs and two rRNAs. The results support Falco as a monophyletic taxon, and F. amurensis has a close relationship with the clade containing F. cherrug/F. rusticolus/F. peregrinus.

The complete mitochondrial genome of red-tailed laughingthrush (Garrulax milnei)

In this study, the complete mitochondrial genome of Garrulax milnei was sequenced for the first time. This mitogenome is 17,871bp in length and it contains 22 tRNA genes, 13 protein-coding genes, 2 rRNA genes, 1 control region and 1 extra pseudo-control region. The base composition of the mitochondrial genome is 29.7% A, 24.5% T, 14.2% G and 31.6% C. The phylogenetic analysis based on the 12 protein-coding genes (except for ND6 gene) showed that G. milnei clusters with other two species that belong to genus Garrulax.

The complete mitochondrial genome of Japanese sparrowhawk (Accipiter gularis) and the phylogenetic relationships among some predatory birds

Phylogenetic relationships among raptors, especially various groups are rather complex and controversial. We determined the complete mtDNA of Japanese sparrowhawk, and estimated phylogenetic trees based on the complete mtDNA alignment of it and 36 other raptor species, to clarify raptor phylogenetics. Phylogenetic trees were also estimated using a multiple sequence alignment of 12S rRNA and 16S rRNA from 81 typical species in GenBank, to further clarify the phylogenetic relationships of several groups among the raptors. The new mtDNA is a circular molecule, 17 917 bp in length, containing the 37 typical genes, with a pseudo-control region. ATG is generally the start codon, TAA is the most frequent stop codon. All tRNAs can be folded into canonical cloverleaf secondary structures except for tRNASer (AGY) and tRNALeu (CUN), which are missing the “DHU” arm. Phylogenetic relationships demonstrate that raptors can be divided into four branches: Accipitriformes, Falconiformes, Strigiformes and Caprimulgiformes in this study. We suggest that Accipitriformes should to be an independent order, Accipitriformes. The results also indicate that Accipitriformes contains three clades: Accipitridae, Pandionidae and Sagittariidae. Strigiformes includes species from Tytonidae and Strigidae. Caprimulgiformes contains Aegothelidae and Caprimulgidae.

Complete mitochondrial genome of Pycnonotus xanthorrhous (Passeriformes, Pycnonotidae) and phylogenetic consideration

The complete mitochondrial genome (mitogenome) of Pycnonotus xanthorrhous was sequenced via next generation sequencing. The full length of the circular genome is 16,952 bp. It consists of 37 typical animal mitochondrial genes including 13 protein-coding genes (PCGs), 22 transfer RNA (tRNA) and 2 ribosomal RNA (rRNA) genes. P. xanthorrhous also contains one control region (CR) and one pseudo-control region, and shares the identical gene arrangements with sequenced Pycnonotus spp. which differs from the typical vertebrates gene order. Phylogenetic analyses indicates that Passerida sensu stricto contains three major clades and the core Sylvioidea form a monophyletic group. Furthermore, we investigated the evolution of control region within this lineage and revealed the multiple independent origins of duplicate control region.

Duplication of the mitochondrial control region is associated with increased longevity in birds.

Despite a number of biochemical and lifestyle differences which should increase risk of oxidative damage to their mitochondrial DNA (mtDNA) and thus reduce expected lifespan, avian species often display longer lifespans than mammals of similar body mass. Recent work in mammalian ageing has demonstrated that functional mitochondrial copy number declines with age. We noted that several bird species display duplication of the control region (CR) of the mtDNA to form a pseudo-control region (YCR), apparently an avian-specific phenomenon. To investigate whether the presence of this duplication may play a similar role in longevity to mitochondrial copy number in mammals, we correlated body mass and longevity in 92 avian families and demonstrate a significant association. Furthermore, outlier analysis demonstrated a significant (p=0.01) difference associated with presence of the YCR duplication in longer-lived avian species. Further research is required to determine if the YCR does indeed alter mitochondrial function or resilience to oxidative damage, but these findings provide an intriguing hint of how mitochondrial sequences may be related to an extended lifespan.

Complete mitochondrial genome of the gyrfalcon Falco rusticolus (Aves, Falconiformes, Falconidae)

The complete mitochondrial genome sequence of gyrfalcon (Falco rusticolus), the largest of the true falcons, was characterized using next generation sequencing. The mitogenome was 18 218 bp long, and comprised of 13 protein-coding genes (PCGs), 22 tRNA, 2 rRNA and two non-coding regions; a control region (D-loop) harboring two tandem repeats 80 bp and 56 bp long and a pseudo-control region (ΨD-loop) with a tandem repeat 27 bp long. All genes were encoded on the + strand except ND6 and 8 tRNA genes.

The complete mitochondrial genome sequence of Eophona migratoria (Passeriformes Fringillidae)

The complete mitochondrial genome (mitogenome) sequence of Eophona migratoria was determined by shotgun sequencing and reported for the first time using the muscle tissue. The total length of the sequence is 16,798 bp, which contains 13 protein-coding genes, 22 transfer RNA genes, 2 ribosomal RNA genes, 1 control region, and 1 extra pseudo-control region. A phylogenetic analysis on the basis of 12 protein-coding genes of 14 passeriformes species’ mitochondrial genomes using maximum-likelihood (ML) demonstrated that Coccothraustes coccothraustes is the most close to E. migratoria.

The complete mitochondrial genome sequence of Buteo hemilasius (Falconiformes: Accipitridae)

In this study, the complete mitochondrial genome of the Upland Buzzard (Buteo hemilasius) was sequenced and reported for the first time using the muscle tissue. The mitochondrial genome is a circular molecule of 18 079 bp in length, consisting of 13 protein-coding genes, 22 transfer RNA genes, 2 ribosomal RNA genes, 1 control region, and 1 extra pseudo-control region. A phylogenetic analysis on the basis of 12 protein-coding genes (except ND6 gene) of 14 Falconiformes species’ mitochondrial genomes using maximum-likelihood (ML) and Bayesian inference (BI) demonstrated that all species cluster into two clades and B. hemilasius is close to B. buteo.

Complete mitochondrial genome and the phylogenetic position of the Lesser Cuckoo, Cuculus poliocephalus (Aves: Cuculiformes)

The complete mitochondrial genome of the Lesser Cuckoo Cuculus poliocephalus was determined using next-generation sequencing. Phylogenetic analyses with 20 cuckoo species and six genes (12S, ATP6, CYTb, ND2, ND3, and ND6) strongly verified the identity of our sample as grouping with C. poliocephalus, which was sister to a clade of other Cuculus spp., including C. canorus, C. micropterus, and C. saturatus. The mitogenomic length of C. poliocephalus was 17 508 bp, including 13 protein-coding genes, 22 transfer RNA genes, two ribosomal RNA genes, one control region with 48 bp unit tandem repeats close to 3′ end, and one short pseudo-control region with 33 tandem repeats of CAACAAA. An extra nucleotide (T) was identified at position 174 of ND3. The mitogenome of C. poliocephalus will contribute to studies of mitogenomic evolution, the phylogenetic relationship of cuckoos, and the co-evolutionary pattern between brood parasitic birds and their hosts.

Complete mitochondrial genomes of the white-browed piculet (Sasia ochracea, Picidae) and pale-billed woodpecker (Campephilus guatemalensis, Picidae)

The mitochondrial genome of the white-browed piculet Sasia ochracea (Piciformes, Picidae) and the pale-billed woodpecker Campephilus guatemalensis (Piciformes, Picidae) were sequenced using a mixed strategy of Sanger and next-generation sequencing methods. The size of the circular mitochondrial genomes were 16 908 and 16 856 bp, respectively, and include 13 protein-coding genes, 22 transfer tRNAs, 2 ribosomal RNAs, a control region and a reduced pseudo control region. The functional control region was located between the tRNAThr and tRNAPro, as found in the two other Piciformes for which complete mtDNA data are available. The length of the pseudo-control region in the white-browed piculet (103 bp) and pale-billed woodpecker (87 bp) is similar to the size of that region in Dryocopus pileatus (60 bp) and much shorter that the length of this region in Pteroglossus azara (1493 bp), suggesting that size reduction occurred before the last common ancestor of the piculets and woodpeckers.

The complete mitochondrial genome of Accipiter virgatus and evolutionary history of the pseudo-control regions in Falconiformes

The complete mitochondrial genome sequence of Accipiter virgatus was determined. This mt-genome was 17,952 bp in length and consisted of 22 tRNA genes, 13 protein-coding genes, 2 rRNA genes, one control region (CR) and one pseudo-control region (CCR). Phylogenetic analyses of 14,644 bp of mitochondrial DNA (12 protein-coding genes, 2 rRNAs and 22 tRNAs) revealed the phylogenetic position of Cathartidae (Cathartes aura) was more closer to Ciconiidae (storks) than Accipitridae. To investigate the divergence times of the CCRs in Falconiformes, detailed analyses of the noncoding regions (CR and CCR) were performed. We found the recently reported novel gene order in Falconiformes had multiple independent origins and hence cannot be used to infer phylogenetic lineages. Indeed, the molecular clock suggested the CCR in Falconidae emerged about 65.4 million years (Mya), while that in Pandionidae–Accipitridae clade emerged about 19.16 Mya. The intra-genomic homology between the noncoding regions was detected in Spilornis cheela, which supporting the duplication hypothesis. Furthermore, the structure of CCR should be featured by a region containing tandem repeats as two definitely separated clusters of tandem repeats were found. The findings presented here should be considered in future phylogenetic and evolutionary studies targeting the pseudo-control regions of all Falconiformes species.

Complete mitochondrial genome of Himalayan buzzard (Buteo buteo burmanicus)

In this study, the complete sequence of the mitochondrial (mt) genome of Buteo buteo burmanicus was determined. This mitogenome was 18,231 bp in length, containing 13 protein-coding genes, 2 rRNA genes, 22 tRNA genes, a control region (CR) and a pseudo-control region (ψCR). The overall base composition of the heavy strand was A, 30.8%; G, 13.2%; C, 31.8%; and T, 24.2%, with a slight AT bias of 65.1%. The complete mitogenomic data may provide more informative for phylogenetic approach for soft corals phylogeny especially for Buteo species.

The complete mitochondrial genome sequence of the Sparrowhawk (Accipiter nisus)

In this study, the complete mitochondrial genome of the Sparrowhawk (Accipiter nisus) was sequenced and reported for the first time using muscle tissue. Sequence analysis showed its genome structure was in accordance with other Accipitridae species, which contains 2 rRNA genes, 22 tRNA genes, 13 protein-coding genes, 1 control region and 1 extra pseudo-control region, and its total length is 18,647 bp. An extra nucleotide (C) was determined at position 174 relative to the ND3 sequence, and an insertion of three adenines was found directly preceding the stop codon of Cytb.