scholarly journals Complete Mitogenome of Endangered and Endemic Nicobar Treeshrew (Tupaia Nicobarica) and Comparison with Other Scandentians

Author(s):  
Shantanu Kundu ◽  
Avas Pakrashi ◽  
Manokaran Kamalakannan ◽  
Devkant Singha ◽  
Kaomud Tyagi ◽  
...  

Abstract The Nicobar treeshrew (Tupaia nicobarica) is an endangered smaller mammal endemic to the Nicobar Island of the Andaman Sea, India regarded as an alternative experimental animal model in biomedical research. The present study aimed to assemble the first mitochondrial genome of T. nicobarica to elucidate evolutionary relationship. The structure and variation of the novel mitochondrial genome were analyzed and compared with other Scandentians. The complete mitogenome (17,164 bp) encodes 37 genes, including 13 protein-coding genes (PCGs), 22 transfer RNA (tRNAs), two ribosomal RNA (rRNAs), and one control region (CR). Most of the genes were encoded on majority strand, except nad6 and eight tRNAs. The nonsynonymous/synonymous ratio in all PCGs indicates strong negative selection among all Tupaiidae species. The comparative study of CRs revealed the occurrence of tandem repeats (CGTACA) found in T. nicobarica. The phylogenetic analyses (ML and BA) showed distinct clustering of T. nicobarica with high branch supports and depict a substantial divergence time (11.4 to 18.8 MYR) from the ancestor lineage of Tupaiidae. The 16S rRNA dataset corroborates the taxonomic rank of two subspecies of T. nicobarica from the Great and Little Nicobar Islands. The present study suggests the assembly of whole-genome to improve the understanding of evolutionary relationships of treeshrews and its implication in biomedical research.

Genetics ◽  
1997 ◽  
Vol 146 (3) ◽  
pp. 995-1010 ◽  
Author(s):  
Rafael Zardoya ◽  
Axel Meyer

The complete nucleotide sequence of the 16,407-bp mitochondrial genome of the coelacanth (Latimeria chalumnae) was determined. The coelacanth mitochondrial genome order is identical to the consensus vertebrate gene order which is also found in all ray-finned fishes, the lungfish, and most tetrapods. Base composition and codon usage also conform to typical vertebrate patterns. The entire mitochondrial genome was PCR-amplified with 24 sets of primers that are expected to amplify homologous regions in other related vertebrate species. Analyses of the control region of the coelacanth mitochondrial genome revealed the existence of four 22-bp tandem repeats close to its 3′ end. The phylogenetic analyses of a large data set combining genes coding for rRNAs, tRNA, and proteins (16,140 characters) confirmed the phylogenetic position of the coelacanth as a lobe-finned fish; it is more closely related to tetrapods than to ray-finned fishes. However, different phylogenetic methods applied to this largest available molecular data set were unable to resolve unambiguously the relationship of the coelacanth to the two other groups of extant lobe-finned fishes, the lungfishes and the tetrapods. Maximum parsimony favored a lungfish/coelacanth or a lungfish/tetrapod sistergroup relationship depending on which transversion:transition weighting is assumed. Neighbor-joining and maximum likelihood supported a lungfish/tetrapod sistergroup relationship.


2018 ◽  
Author(s):  
Shantanu Kundu ◽  
Vikas Kumar ◽  
Kaomud Tyagi ◽  
Rajasree Chakraborty ◽  
Iftikar Rahaman ◽  
...  

Complete mitochondrial genomes of Indian tent turtle, Pangshura tentoria was sequenced and annotated as 16,657 bp in length. This first assembly was encoded by 37 genes: 13 protein coding genes (PCGs), 22 transfer RNA (tRNAs), two ribosomal RNA (rRNAs) as similar to the typical vertebrate mitochondrial gene arrangement. The complete mitogenome has a base composition of A (33.30%), G (13.54%), C (27%), and T (26.13%). Most of the genes were encoded on major strand, except for the eight tRNAs and one PCG (nad6). Almost all PCGs were starting with an ATG initiation codon, except for cytochrome oxidase subunit 1 (cox1) with ‘GTG’ and NADH dehydrogenase subunit 5 (nad5) with ‘ATA’. The typical termination codons, ‘TAA’ and ‘AGA’ has been observed in NADH dehydrogenase subunit 4l (nad4l) and NADH dehydrogenase subunit 6 (nad6) respectively; and others were used incomplete stop codons. The Relative Synonymous Codon Usage (RSCU) analysis revealed the maximum abundance of Alanine, Isoleucine, Leucine, and Threonine in P. tentoria. Codon distribution per thousand codon (CDsPT) values for all the amino acids showed the maximum values were present for Leucine in all geoemydid turtles. Further, the PCGs showed non-synonymous (Ka)/synonymous (Ks) values were <1 that indicated a strong negative selection among the studied species. The tRNAs were folded into classic clover-leaf secondary structures, except for trnS (GCT), lacking of the conventional DHU arm or stem. Further, the 10 tRNAs showed G-T mismatches and forming weak bonds. In the control region (CR) of P. tentoria, a single tandem repeat of eight base pairs (TTCTCTTT) was resulted with two copy numbers. The comparative study of CR with other geoemydid turtles revealed the numbers of tandem repeats were frequent in the 3´ end and structural characteristic were species-specific. The Maximum Likelihood (ML) phylogeny showed 32 geoemydid turtles were clustered distinctly with high bootstrap support and congruent with the previous phylogenetic hypothesis. Further, the representative mitogenome sequences of other family/suborder were depicted discrete clades in the ML tree. The study argued the complete mitochondrial genome sequence of P. tentoria and comparative mitochondriomics of geoemydid turtles would be useful for further phylogenetic reconciliation and evolutionary research.


2018 ◽  
Author(s):  
Shantanu Kundu ◽  
Vikas Kumar ◽  
Kaomud Tyagi ◽  
Rajasree Chakraborty ◽  
Iftikar Rahaman ◽  
...  

Complete mitochondrial genomes of Indian tent turtle, Pangshura tentoria was sequenced and annotated as 16,657 bp in length. This first assembly was encoded by 37 genes: 13 protein coding genes (PCGs), 22 transfer RNA (tRNAs), two ribosomal RNA (rRNAs) as similar to the typical vertebrate mitochondrial gene arrangement. The complete mitogenome has a base composition of A (33.30%), G (13.54%), C (27%), and T (26.13%). Most of the genes were encoded on major strand, except for the eight tRNAs and one PCG (nad6). Almost all PCGs were starting with an ATG initiation codon, except for cytochrome oxidase subunit 1 (cox1) with ‘GTG’ and NADH dehydrogenase subunit 5 (nad5) with ‘ATA’. The typical termination codons, ‘TAA’ and ‘AGA’ has been observed in NADH dehydrogenase subunit 4l (nad4l) and NADH dehydrogenase subunit 6 (nad6) respectively; and others were used incomplete stop codons. The Relative Synonymous Codon Usage (RSCU) analysis revealed the maximum abundance of Alanine, Isoleucine, Leucine, and Threonine in P. tentoria. Codon distribution per thousand codon (CDsPT) values for all the amino acids showed the maximum values were present for Leucine in all geoemydid turtles. Further, the PCGs showed non-synonymous (Ka)/synonymous (Ks) values were <1 that indicated a strong negative selection among the studied species. The tRNAs were folded into classic clover-leaf secondary structures, except for trnS (GCT), lacking of the conventional DHU arm or stem. Further, the 10 tRNAs showed G-T mismatches and forming weak bonds. In the control region (CR) of P. tentoria, a single tandem repeat of eight base pairs (TTCTCTTT) was resulted with two copy numbers. The comparative study of CR with other geoemydid turtles revealed the numbers of tandem repeats were frequent in the 3´ end and structural characteristic were species-specific. The Maximum Likelihood (ML) phylogeny showed 32 geoemydid turtles were clustered distinctly with high bootstrap support and congruent with the previous phylogenetic hypothesis. Further, the representative mitogenome sequences of other family/suborder were depicted discrete clades in the ML tree. The study argued the complete mitochondrial genome sequence of P. tentoria and comparative mitochondriomics of geoemydid turtles would be useful for further phylogenetic reconciliation and evolutionary research.


2018 ◽  
Author(s):  
Shantanu Kundu ◽  
Vikas Kumar ◽  
Kaomud Tyagi ◽  
Rajasree Chakraborty ◽  
Devkant Singha ◽  
...  

AbstractThe complete mitochondrial genome (16796 bp) of an endangered freshwater turtle, Nilssonia nigricans was firstly sequenced and annotated. The mitogenome was encoded by 37 genes and a major non-coding Control Region (CR). The mitogenome was A+T biased (62.16%) and spread with six overlapping and 19 intergenic spacer regions. The initiation codons were exceptionally changed as ATA, ATT, and ATC in three Protein-coding genes (PCGs) and a single base (A, T, and C) incomplete termination codons in nine PCGs. The Relative synonymous codon usage (RSCU) value was consistent among all the studied species; exception with significant reduction of Serine (S) frequency in N. nigricans, N. formosa, and R. swinhoei. The secondary structure of N. nigricans showed a lack of conventional dihydrouridine (DHU) arm in trnS (GCT), as well as formed a small loop structure in the acceptor stem of both trnR (TCG) and trnH (GTG). The mitogenome of N. nigricans also revealed two unique tandem repeats (ATTAT)8, and (TATTA)20 in CR. Further, the average Ka/Ks values of 13 PCGs were indicating a strong natural selection in the studied Trionychidae species. The constructed Maximum Likelihood (ML) phylogeny by PCGs shows cohesive clustering of N. nigricans with N. formosa. The resulted phylogeny illustrated the similar topology by all studied species from different taxonomic ranks and supported the previous taxonomic classification. Moreover, further taxon sampling from different taxonomic hierarchy, and their mitogenomics study is vital to reconcile the Testudines phylogeny and assure their evolutionary relationship.


Genes ◽  
2019 ◽  
Vol 10 (9) ◽  
pp. 724 ◽  
Author(s):  
Xiaolei Yu ◽  
Wei Tan ◽  
Huanyu Zhang ◽  
Weiling Jiang ◽  
Han Gao ◽  
...  

In this study, we report the complete mitochondrial genome of Harpalus sinicus (occasionally named as the Chinese ground beetle) which is the first mitochondrial genome for Harpalus. The mitogenome is 16,521 bp in length, comprising 37 genes, and a control region. The A + T content of the mitogenome is as high as 80.6%. A mitochondrial origins of light-strand replication (OL)-like region is found firstly in the insect mitogenome, which can form a stem-loop hairpin structure. Thirteen protein-coding genes (PCGs) share high homology, and all of them are under purifying selection. All tRNA genes (tRNAs) can be folded into the classic cloverleaf secondary structures except tRNA-Ser (GCU), which lacks a dihydrouridine (DHU) stem. The secondary structure of two ribosomal RNA genes (rRNAs) is predicted based on previous insect models. Twelve types of tandem repeats and two stem-loop structures are detected in the control region, and two stem-loop structures may be involved in the initiation of replication and transcription. Additionally, phylogenetic analyses based on mitogenomes suggest that Harpalus is an independent lineage in Carabidae, and is closely related to four genera (Abax, Amara, Stomis, and Pterostichus). In general, this study provides meaningful genetic information for Harpalus sinicus and new insights into the phylogenetic relationships within the Carabidae.


Zootaxa ◽  
2012 ◽  
Vol 3554 (1) ◽  
pp. 30 ◽  
Author(s):  
XUN DAI ◽  
HUAIZHU XUN ◽  
JIAN CHANG ◽  
JIANGUO ZHANG ◽  
BAOWEN HU ◽  
...  

Nesidiocoris tenuis (Reuter) is a zoophytophagous mirid which is considered both as a significant natural enemy and an important pest of crops. The complete mitochondrial genome (mitogenome) of N. tenuis was determined using long PCR and a primer walking sequencing strategy. The genome is 17, 544 bp in length and contains 13 protein-coding genes (PCGs), 22 transfer RNA (tRNA) genes, two ribosomal RNA genes (lrRNA and srRNA), and a duplicate control region. The gene order of this newly sequenced genome is identical with the ground plan of insects. The nucleotide composition is biased toward adenine and thymine with a high AT content (75.0%). The most frequent codons are ATA, TTA, TTT, and ATT. All the PCGs initiate with the standard start codon ATN. All tRNAs have the classic cloverleaf structures, with the exception of tRNASer(UCG), which lacks the dihydrouridine (DHU) arm. Secondary structures of the two ribosomal RNAs were shown referring to previous models. Variable numbers of tandem repeats were detected in the control region. The phylogenetic analyses shows that N. tenuis is the sister group to Lygus lineolaris (Palisot de Beauvois).


Zootaxa ◽  
2020 ◽  
Vol 4732 (3) ◽  
pp. 461-473
Author(s):  
JIAJIA CHEN ◽  
JINJUN CAO ◽  
MENGDAN CHEN ◽  
SIJIN CHEN ◽  
WEIHAI LI ◽  
...  

We sequenced the complete mitochondrial genome (mitogenome) of a stonefly, Amphinemura claviloba (Wu, 1973), of the family Nemouridae (Insecta: Plecoptera). The mitogenome was 15,707 bp long and contained typical 37 genes with an A+T content of 68.5%. All protein-coding genes (PCGs) use standard initiation codons (methionine and isoleucine), except ND1 and ND5 which starts with TTG and GTG, respectively. Two of the 13 PCGs harbor the incomplete termination codon. All tRNA genes have typical clover secondary structures, except the dihydrouridine (DHU) arm of tRNASer(AGN) forms a simple loop. Secondary structure models of the ribosomal RNA genes of A. claviloba are similar to those proposed for other insects. We also found some structural elements in the control region, such as tandem repeats, poly-C stretch and microsatellite-like elements, etc. Phylogenetic analyses showed the clades for the Nemoura, Amphinemura, and (Mesonemoura + Sphaeronemoura + Indonemoura + Protonemura) are well supported in a polytomy. 


2021 ◽  
Vol 6 (8) ◽  
pp. 2442-2444
Author(s):  
Haibo Zhang ◽  
Xue Gou ◽  
Shize Li ◽  
Cheng Wang ◽  
Caichun Peng ◽  
...  

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kun Zhang ◽  
Kehua Zhu ◽  
Yifan Liu ◽  
Hua Zhang ◽  
Li Gong ◽  
...  

AbstractThe structure and gene sequence of the fish mitochondrial genome are generally considered to be conservative. However, two types of gene arrangements are found in the mitochondrial genome of Anguilliformes. In this paper, we report a complete mitogenome of Muraenesox cinereus (Anguilliformes: Muraenesocidae) with rearrangement phenomenon. The total length of the M. cinereus mitogenome was 17,673 bp, and it contained 13 protein-coding genes, two ribosomal RNAs, 22 transfer RNA genes, and two identical control regions (CRs). The mitochondrial genome of M. cinereus was obviously rearranged compared with the mitochondria of typical vertebrates. The genes ND6 and the conjoint trnE were translocated to the location between trnT and trnP, and one of the duplicated CR was translocated to the upstream of the ND6. The tandem duplication and random loss is most suitable for explaining this mitochondrial gene rearrangement. The Anguilliformes phylogenetic tree constructed based on the whole mitochondrial genome well supports Congridae non-monophyly. These results provide a basis for the future Anguilliformes mitochondrial gene arrangement characteristics and further phylogenetic research.


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