We sequenced and annotated the complete mitochondrial genome (mitogenome) of Bactrocera diaphora (Diptera: Tephtitidae), which is an economically important pest in the southwest area of China, India, Sri Lanka, Vietnam and Malaysia. This mitogenome is 15 890 bp in length with an A + T content of 74.103%, and contains 37 typical animal mitochondrial genes that are arranged in the same order as that of the inferred ancestral insects. All protein-coding genes (PCGs) start with a typical ATN codon, except cox1 that begins with TCG. Ten PCGs stop with termination codon TAA or TAG, whereas cox1, nad1 and nad5 have single T-- as the incomplete stop codon. All of the transfer RNA genes present the typical clover leaf secondary structure except trnS1 (AGN) with a looping D-arm. The A + T-rich region is located between rrnS and trnI with a length of 946 bp, and contains a 20 bp poly-T stretch and 22 bp poly-A stretch. Except the control region, the longest intergenic spacer is located between trnR and trnN that is 94 bp long with an excessive high A + T content (95.74%) and a microsatellite-like region (TA)13.
We describe the characteristics of complete mitogenome of C. brachyotis in this article. The complete mitogenome of C. brachyotis is 16,701 bp long with a total base composition of 32.4% A, 25.7% T, 27.7% C and 14.2% G. The mitogenome consists of 13 protein-coding genes (11,408 bp), (KM659865) two rRNA (12S rRNA and 16S rRNA) genes (2,539 bp), 22 tRNA genes (1518 bp) and one control region (1239 bp).
Consensus on the optimal high-throughput sequencing (HTS) approach to examine biodiversity in mixed terrestrial arthropod samples has not been reached. Metatranscriptomics could increase the proportion of taxonomically informative mitochondrial reads in HTS outputs but has not been investigated for terrestrial arthropod samples. We compared the efficiency of 16S rRNA metabarcoding, metagenomics and metatranscriptomics for detecting species in a mixed terrestrial arthropod sample (pooled DNA/RNA from 38 taxa). 16S rRNA metabarcoding and nuclear rRNA-depleted metatranscriptomics had the highest detection rate with 97% of input species detected. Based on cytochrome c oxidase I, metagenomics had the highest detection rate with 82% of input species detected, but metatranscriptomics produced a larger proportion of reads matching (Sanger) reference sequences. Metatranscriptomics with nuclear rRNA depletion may offer advantages over metabarcoding through reducing the number of spurious operational taxonomic units while retaining high detection rates, and offers natural enrichment of mitochondrial sequences which may enable increased species detection rates compared with metagenomics.
Environmental DNA detection has emerged as a powerful tool to monitor aquatic species without the need for capture or visual identification and is particularly useful for rare or elusive species. Our objective was to develop an eDNA approach for detecting the southern river terrapin (Batagur affinis) in Malaysia. We designed species-specific primers for a fragment of B. affinis mtDNA and evaluated their effectiveness in silico, in vitro and in situ. The primers amplified 110 bp of the cytochrome b mtDNA sequence of B. affinis from aquarium water samples housing nine juvenile B. affinis. We also successfully detected B. affinis eDNA from river samples taken from a site where turtles were known to be in the vicinity. Prospects and challenges of using an eDNA approach to help determine the distribution of B. affinis, essential information for an effective conservation plan, are discussed.
To examine the phylogeographical pattern of Tetrancistrum nebulosi (Monogenea, Dactylogyridae) in the South China Sea, fragments of mitochondrial cytochrome c oxidase subunit I and NADH dehydrogenase subunit 2 genes were obtained for 220 individuals collected from 8 localities along the southeast coast of China and 1 locality in Terengganu, Malaysia. Based on these two genes, two and three distinct clades with geographic signals were revealed on the phylogenetic trees respectively. The divergence between these clades was estimated to occur in the late Pleistocene. Analysis of molecular variance and pairwise FSTsuggested a high rate of gene flow among individuals sampled from the Chinese coast, but with obvious genetic differentiation from the Malaysian population. Mismatch distribution and neutrality tests indicated that the T. nebulosi population experienced expansion in Pleistocene low sea level periods. Vicariance was considered to account for the genetic divergence between Chinese and Malaysian populations, while sea level fluctuations and mainland-island connections during glacial cycles were associated with the slight genetic divergence between the populations along the mainland coast of China and those off Sanya. On the contrary, oceanographic circulations and host migration could lead to genetic homogeneity of populations distributed along the mainland coast of China.
The mitochondrial genome sequence of the purple mottled shore crab, Cyclograpsus granulosus, is documented (GenBank accession number: LN624373), which makes it the third for genera of the superfamily Grapsoidea. Cyclograpsus granulosus has a mitogenome of 16,300 bp consisting of 13 protein-coding genes, two ribosomal subunit genes, 22 transfer RNAs and a non-coding AT-rich region. The base composition of the C. granulosus mitogenome is 36.15% for T, 19.54% for C, 33.14% for A and 11.17% for G, with an AT bias of 69.29%. The mitogenome gene order is atypical for the brachyuran crabs, but is identical to species of the genus Eriocheir from the same family.
The mitochondrial genome sequence of the porcellanid crab, Petrolisthes haswelli is provided, making it the second for the family Porcellanidae and the third for the superfamily Galatheoidea. Petrolisthes haswelli has a mitogenome of 15,348 bp consisting of 13 protein-coding genes, two ribosomal subunit genes, 22 transfer RNAs and a non-coding AT-rich region. The base composition of the P. haswelli mitogenome is 35.66% for T, 18.65% for C, 34.35% for A and 11.34% for G, with an AT bias of 70.01%. The mitogenome gene order is identical to the mitogenome of Neopetrolisthes maculatus, the only other species of the family with a sequenced mitogenome.
The mitochondrial genome sequence of the ghost crab, Ocypode ceratophthalmus, is documented (GenBank accession number: LN611669) in this article. This is the first mitogenome for the family Ocypodidae and the second for the order Ocypodoidea. Ocypode ceratophthalmus has a mitogenome of 15,564 base pairs consisting of 13 protein-coding genes, two ribosomal subunit genes, 22 transfer RNAs and a non-coding AT-rich region. The base composition of the O. ceratophthalmus mitogenome is 35.78% for T, 19.36% for C, 33.73% for A and 11.13% for G, with an AT bias of 69.51% and the gene order is the typical arrangement for brachyuran crabs.
The Mictyris longicarpus (soldier crab) complete mitochondrial genome sequence is reported making it the first for the family Mictyridae and the second for the superfamily Ocypodoidea. The mitogenome is 15,548 base pairs made up of 13 protein-coding genes, 2 ribosomal subunit genes, 22 transfer RNAs and a non-coding AT-rich region. The soldier crab mitogenome gene order is characteristic of brachyuran crabs with a base composition of 36.58% for T, 19.15% for C, 32.43% for A and 11.83% for G, with an AT bias of 69.01%.
The mitochondrial genome sequence of the stone crab, Myomenippe fornasinii, second of the superfamily Eriphioidea is documented. Myomenippe fornasinii has a mitogenome of 15,658 base pairs consisting of 13 protein-coding genes, 2 ribosomal subunit genes, 22 transfer RNAs and a non-coding AT-rich region. The base composition of the M. fornasinii mitogenome is 36.10% for T, 18.52% for C, 35.48% for A, and 9.90% for G, with an AT bias of 71.58%. The mitogenome gene order conforms to what is the standard arrangement for brachyuran crabs.
The mitochondrial genome sequence of the Morton Bay bug, Thenus orientalis, is documented, which makes it the second mitogenome for species of the family Scyllaridae and the ninth for members of the superfamily Palinuroidae. Thenus orientalis has a mitogenome of 16,826 base pairs consisting of 13 protein-coding genes, 2 ribosomal subunit genes, 23 transfer RNAs, and a non-coding AT-rich region. The base composition of the T. orientalis mitogenome is 31.31% for T, 23.77% for C, 31.05% for A, and 13.87% for G, with an AT bias of 62.36%. In addition to a duplicated trnS1 and several other tRNA gene rearrangements, the mitogenome gene order has novel protein coding gene order with the nad6 and cob genes translocated as a block to a location downstream of the nad3 gene.
The complete mitochondrial genome of the swimming crab Thalamita crenata was obtained from a partial genome scan using the MiSeq sequencing system. The Thalamita crenata mitogenome has 15,787 base pairs (70% A+T content) made up of 13 protein-coding genes, 2 ribosomal subunit genes, 22 transfer RNAs, and a putative 897 bp non-coding AT-rich region. This Thalamita mitogenome sequence is the first for the genus and the eighth for the family Portunidae.
The complete mitochondrial genome of the moon crab Ashtoret lunaris was obtained from a partial genome scan using the MiSeq sequencing system. The Ashtoret lunaris mitogenome is 15,807 base pairs in length (70% A + T content) and made up of 13 protein-coding genes, 2 ribosomal subunit genes, 22 transfer RNAs, and a putative 956 bp non-coding AT-rich region. This A. lunaris mitogenome sequence is the first for the genus, as well as the family Matutidae and superfamily Calappoidea.
Certain species of Phlebotomine sandflies (Diptera: Psychodidae) are vectors of the protozoa which causes leishmaniasis. Sandflies are found breeding in enclosed places like caves. Thailand is a popular tourist destination, including for ecotourism activities like caving, which increases the risk of contact between tourists and sandflies. Surveillance of sandflies is important for monitoring this risk but identification of species based on morphology is challenged by phenotypic plasticity and cryptic diversity. DNA barcodes have been used for the identification of sandflies in Thailand. We collected sandflies using CDC light trap from four tourist caves in Northern Thailand. Female sandflies were provisionally sorted into 13 morphospecies and 19 unidentified specimens. DNA was extracted from the thorax and legs of sandflies and the DNA barcode region of cytochrome c oxidase I mtDNA amplified and sequenced. The specimens were sorted into 22 molecular operational taxonomic units (MOTU) based on the 145 DNA barcodes, which is significantly more than the morphospecies. Several of the taxa thought to be present in multiple caves, based on morphospecies sorting, split into cave-specific MOTU which likely represent cryptic species. Several MOTU reported in an earlier study from Wihan Cave, Thailand, were also found in these caves. This supports the use of DNA barcodes to investigate species diversity of sandflies and their useful role in surveillance of sandflies in Thailand.
In this study, the complete mitogenome sequence of the Clarion angelfish, Holacanthus clarionensis (Perciformes: Pomacanthidae) has been sequenced by next-generation sequencing method. The length of the assembled mitogenome is 16,615 bp, including 13 protein coding genes, 22 transfer RNAs, and two ribosomal RNAs genes. The overall base composition of Clarion angelfish is 28.3% for A, 29.3% for C, 16.5% for G, 25.9% for T and show 85% identities to flame angelfish Centropyge loriculus. The complete mitogenome of the Clarion angelfish provides essential and important DNA molecular data for further phylogeography and evolutionary analysis for marine angelfish phylogeny.
In this study, the complete mitogenome sequence of the Blue-face angelfish, Pomacanthus xanthometapon (Perciformes: Pomacanthidae) has been sequenced by the next-generation sequencing method. The assembled mitogenome consisting of 16,533 bp includes 13 protein coding genes, 22 transfer RNAs, and two ribosomal RNAs genes. The overall base composition of Blue-face angelfish is 28.7% for A, 28.9% for C, 15.9% for G, 26.6% for T and show 84% identities to flame angelfish Centropyge loriculus. The complete mitogenome of the Blue-face angelfish provides essential and important DNA molecular data for further phylogeography and evolutionary analysis for marine angelfish phylogeny.
This study is aimed at establishing a baseline on the genetic diversity of the Acropora corals of Sabah, North Borneo based on variations in the partial COI and CYB nucleotide sequences. Comparison across 50 shallow-water Acropora morphospecies indicated that the low substitution rates in the two genes were due to negative selection and that rate heterogeneity between them was asymmetric. CYB appeared to have evolved faster than COI in the Acropora as indicated by differences in the rate of pairwise genetic distance, degrees of transition bias (Ts/Tv), synonymous-to-nonsynonymous rate ratio (dN/dS), and substitution patterns at the three codon positions. Despite the relatively high haplotype diversity (Hd), nucleotide diversity (π) of the haplotype datasets was low due to stringent purifying selection operating on the genes. Subsequently, we identified individual COI and CYB haplotypes that were each extensively shared across sympatrically and allopatrically distributed Indo-Pacific Acropora. These reciprocally common mtDNA types were suspected to be ancestral forms of the genes whereas other haplotypes have mostly evolved from autoapomorphic mutations which have not been fixed within the species even though they are selectively neutral. To our knowledge, this is the first report on DNA barcodes of Acropora species in North Borneo and this understanding will play an important role in the management and conservation of these important reef-building corals.
Sandflies vary in their distributions and role in pathogen transmission. Attempts to record distributions of sandflies in Thailand have faced difficulties due to their high abundance and diversity. We aim to provide an insight into the diversity of sandflies in Thailand by (i) conducting a literature review, and (ii) DNA barcoding sandflies collected from Wihan Cave where eight morphologically characterized species were recorded. DNA barcodes generated for 193 sandflies fell into 13 distinct species clusters under four genera (Chinius, Idiophlebotomus, Phlebotomus and Sergentomyia). Five of these species could be assigned Linnaean species names unambiguously and two others corresponded to characterized morphospecies. Two species represented a complex under the name Sergentomyia barraudi while the remaining four had not been recognized before in any form. The resulting species checklist and DNA barcode library contribute to a growing set of records for sandflies which is useful for monitoring and vector control.
In this study, the complete mitogenome sequence of two moray eels of Gymnothorax formosus and Scuticaria tigrina (Anguilliformes: Muraenidae) has been sequenced by the next-generation sequencing method. The assembled mitogenome, with the length of 16,558 bp for G. formosus and 16,521 bp for S. tigrina, shows 78% identity to each other. Both mitogenomes follow the typical vertebrate arrangement, including 13 protein coding genes, 22 transfer RNAs, two ribosomal RNAs genes, and a non-coding control region of D-loop. The length of D-loop is 927 bp (G. formosus) and 850 bp (S. tigrina), which is located between tRNA-Pro and tRNA-Phe. The overall GC content is 45.5% for G. formosus and 47.9% for S. tigrina. Complete mitogenomes of G. formosus and S. tigrina provide essential and important DNA molecular data for further phylogenetic and evolutionary analysis for moray eel.
In this study, the complete mitogenome sequence of the longfang moray, Enchelynassa canina (Anguilliformes: Muraenidae) has been sequenced by the next-generation sequencing method. The length of the assembled mitogenome is 16,592 bp, which includes 13 protein coding genes, 22 transfer RNAs, and 2 ribosomal RNAs genes. The overall base composition of longfang moray is 28.4% for A, 28.0% for C, 18.4% for G, 25.1% for T, and show 82% identities to Kidako moray, Gymnothorax kidako. The complete mitogenome of the longfang moray provides an essential and important DNA molecular data for further phylogeography and evolutionary analysis for moray eel phylogeny.