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Fulltext Evidence for a higher number of species of Odontotermes (Isoptera) than currently known from Peninsular Malaysia from mitochondrial DNA phylogenies

Cheng S, Kirton LG, Panandam JM, Siraj SS, Ng KK, Tan SG

PLoS One, 2011;6(6):e20992.
PMID: 21687629 DOI: 10.1371/journal.pone.0020992

Termites of the genus Odontotermes are important decomposers in the Old World tropics and are sometimes important pests of crops, timber and trees. The species within the genus often have overlapping size ranges and are difficult to differentiate based on morphology. As a result, the taxonomy of Odontotermes in Peninsular Malaysia has not been adequately worked out. In this study, we examined the phylogeny of 40 samples of Odontotermes from Peninsular Malaysia using two mitochondrial DNA regions, that is, the 16S ribosomal RNA and cytochrome oxidase subunit I genes, to aid in elucidating the number of species in the peninsula. Phylogenies were reconstructed from the individual gene and combined gene data sets using parsimony and likelihood criteria. The phylogenies supported the presence of up to eleven species in Peninsular Malaysia, which were identified as O. escherichi, O. hainanensis, O. javanicus, O. longignathus, O. malaccensis, O. oblongatus, O. paraoblongatus, O. sarawakensis, and three possibly new species. Additionally, some of our taxa are thought to comprise a complex of two or more species. The number of species found in this study using DNA methods was more than the initial nine species thought to occur in Peninsular Malaysia. The support values for the clades and morphology of the soldiers provided further evidence for the existence of eleven or more species. Higher resolution genetic markers such as microsatellites would be required to confirm the presence of cryptic species in some taxa.

Matched MeSH terms: Electron Transport Complex IV/genetics
DNA barcoding reveals neritid diversity (Mollusca: Gastropoda) diversity in Malaysian waters

Chee SY, Mohd Nor SA

Mitochondrial DNA A DNA Mapp Seq Anal, 2016 05;27(3):2282-4.
PMID: 25471442 DOI: 10.3109/19401736.2014.987237

This is the first study to identify and determine the phylogenetics of neritids found in Malaysia. In total, twelve species from the family Neritidae were recorded. Ten species were from the genus Nerita and two species were from the genus Neritina. DNA barcodes were successfully assigned to each species. Although some of these species were previously reported in the region, three are only presently reported in this study. The dendrogram showed Nerita and Neritina strongly supported in their respective monophyletic clades. Phylogenetic positions of some species appeared unstable in the trees. This could be due to the differences in a small number of nucleotides, thus minimizing genetic variation between each specimen and species.

Matched MeSH terms: Electron Transport Complex IV/genetics
A multi-locus approach resolves the phylogenetic relationships of the Simulium asakoae and Simulium ceylonicum species groups in Malaysia: evidence for distinct evolutionary lineages

Low VL, Takaoka H, Adler PH, Ya'cob Z, Norma-Rashid Y, Chen CD, et al.

Med Vet Entomol, 2015 Sep;29(3):330-7.
PMID: 25968459 DOI: 10.1111/mve.12120

A multi-locus approach was used to examine the DNA sequences of 10 nominal species of blackfly in the Simulium subgenus Gomphostilbia (Diptera: Simuliidae) in Malaysia. Molecular data were acquired from partial DNA sequences of the mitochondria-encoded cytochrome c oxidase subunit I (COI), 12S rRNA and 16S rRNA genes, and the nuclear-encoded 18S rRNA and 28S rRNA genes. No single gene, nor the concatenated gene set, resolved all species or all relationships. However, all morphologically established species were supported by at least one gene. The multi-locus sequence analysis revealed two distinct evolutionary lineages, conforming to the morphotaxonomically recognized Simulium asakoae and Simulium ceylonicum species groups.

Matched MeSH terms: Electron Transport Complex IV/genetics
Fulltext Reading Mammal Diversity from Flies: The Persistence Period of Amplifiable Mammal mtDNA in Blowfly Guts (Chrysomya megacephala) and a New DNA Mini-Barcode Target

Lee PS, Sing KW, Wilson JJ

PLoS One, 2015;10(4):e0123871.
PMID: 25898278 DOI: 10.1371/journal.pone.0123871

Most tropical mammal species are threatened or data-deficient. Data collection is impeded by the traditional monitoring approaches which can be laborious, expensive and struggle to detect cryptic diversity. Monitoring approaches using mammal DNA derived from invertebrates are emerging as cost- and time-effective alternatives. As a step towards development of blowfly-derived DNA as an effective method for mammal monitoring in the biodiversity hotspot of Peninsular Malaysia, our objectives were (i) to determine the persistence period of amplifiable mammal mtDNA in blowfly guts through a laboratory feeding experiment (ii) to design and test primers that can selectively amplify mammal COI DNA mini-barcodes in the presence of high concentrations of blowfly DNA. The persistence period of amplifiable mammal mtDNA in blowfly guts was 24 h to 96 h post-feeding indicating the need for collecting flies within 24 h of capture to detect mammal mtDNA of sufficient quantity and quality. We designed a new primer combination for a COI DNA mini-barcode that did not amplify blowfly DNA and showed 89% amplification success for a dataset of mammals from Peninsular Malaysia. The short (205 bp) DNA mini-barcode could distinguish most mammal species (including separating dark taxa) and is of suitable length for high-throughput sequencing. Our new DNA mini-barcode target and a standardized trapping protocol with retrieval of blowflies every 24 h could point the way forward in the development of blowfly-derived DNA as an effective method for mammal monitoring.

Matched MeSH terms: Electron Transport Complex IV/genetics
Fulltext Detection of mitochondrial COII DNA sequences in ant guts as a method for assessing termite predation by ants

Fayle TM, Scholtz O, Dumbrell AJ, Russell S, Segar ST, Eggleton P

PLoS One, 2015;10(4):e0122533.
PMID: 25853549 DOI: 10.1371/journal.pone.0122533

Termites and ants contribute more to animal biomass in tropical rain forests than any other single group and perform vital ecosystem functions. Although ants prey on termites, at the community level the linkage between these groups is poorly understood. Thus, assessing the distribution and specificity of ant termitophagy is of considerable interest. We describe an approach for quantifying ant-termite food webs by sequencing termite DNA (cytochrome c oxidase subunit II, COII) from ant guts and apply this to a soil-dwelling ant community from tropical rain forest in Gabon. We extracted DNA from 215 ants from 15 species. Of these, 17.2 % of individuals had termite DNA in their guts, with BLAST analysis confirming the identity of 34.1 % of these termites to family level or better. Although ant species varied in detection of termite DNA, ranging from 63 % (5/7; Camponotus sp. 1) to 0 % (0/7; Ponera sp. 1), there was no evidence (with small sample sizes) for heterogeneity in termite consumption across ant taxa, and no evidence for species-specific ant-termite predation. In all three ant species with identifiable termite DNA in multiple individuals, multiple termite species were represented. Furthermore, the two termite species that were detected on multiple occasions in ant guts were in both cases found in multiple ant species, suggesting that ant-termite food webs are not strongly compartmentalised. However, two ant species were found to consume only Anoplotermes-group termites, indicating possible predatory specialisation at a higher taxonomic level. Using a laboratory feeding test, we were able to detect termite COII sequences in ant guts up to 2 h after feeding, indicating that our method only detects recent feeding events. Our data provide tentative support for the hypothesis that unspecialised termite predation by ants is widespread and highlight the use of molecular approaches for future studies of ant-termite food webs.

Matched MeSH terms: Electron Transport Complex IV/genetics*
Morphological and genetic variations of the freshwater leech, Hirudinaria spp., in Peninsular Malaysia

Chong LK, Ong AH, Tan SG, Taranjeet KA, Peris MM, Sana AM, et al.

Biochem Genet, 2014 Jun;52(5-6):283-95.
PMID: 24535156 DOI: 10.1007/s10528-014-9647-8

In this study the genetic diversity of local freshwater leeches (Hirudinaria spp.) was inferred using mtDNA COI gene analysis and compared with the gross external variations of 26 freshwater leech specimens obtained from the wild and leech farms. Based on a neighbor-joining tree generated from 516 COI base sequences, four distinct clades of Hirudinaria were seen with interspecific genetic divergence in the range of 7.6-14.5%. The external morphological variations based on the presence of stripes, location of gonopores, and anus separated the samples into four morphologically distinct groups matching the four clades obtained from the molecular data. Two black stripes at the ventral region were observed only in specimens found clustered with clades that contained the GenBank-reported H. manillensis, whereas the brown or dark green coloration without stripes on the ventral region was seen in samples that clustered with H. javanica and H. bpling clades.

Matched MeSH terms: Electron Transport Complex IV/genetics
Mitochondrial DNA diversity of mud crab Scylla olivacea (Portunidae) in Peninsular Malaysia: a preliminary assessment

Rosly HA, Nor SA, Yahya K, Naim DM

Mol Biol Rep, 2013 Nov;40(11):6407-18.
PMID: 24062076 DOI: 10.1007/s11033-013-2755-4

A primary factor in population management and wildlife conservation is the delineation of population units derived from descriptions of population genetic structure. Yet, predicting factors that influence the patterns of gene flow in a population particularly at landscape scales remains a major challenge in evolutionary biology. Here we report a population genetic study of the mud crab Scylla olivacea examined based on a 542 bp segment of the mitochondrial DNA cytochrome c oxidase I gene among 91 individuals from six localities in the west and east coast of Peninsular Malaysia. In total 55 unique haplotypes were distinguished with 45 private haplotypes and a single common haplotype shared among all populations studied. The other ten haplotypes were shared among various populations. The sharing of this haplotype reflects the connection of the mangrove areas between east and west coast of Peninsular Malaysia. High haplotype diversity (h = 0.968 ± 0.021; mean ± SD) and low nucleotide diversity (π = 0.120 ± 0.015; mean ± SD) were displayed, which may be indicative of genetic bottleneck events. No significant phylogenetic lineages were recognized using neighbour-joining and maximum parsimony methods. Hierarchical AMOVA analysis indicated that 99.33 % of the genetic variation was contained within populations and 0.67 % occurred among populations, suggesting no geographical patterning among populations studied, supported by F st test. Mismatch distribution analysis showed that the observed distribution of the pairwise mutation differences among haplotypes was multimodal, which is not concordant with a sudden range expansion scenario. However, neutrality tests showed non-significant negative values suggesting that the populations studied may have experienced past population growth, but the expansion may have been restricted to separate local areas that resulted in the non-significant negative Fu's Fs and Tajima's D value. Overall, this present preliminary study was able to be a reference on the phylogenetic relationships and assessment of genetic structure of Scylla sp. in Malaysia.

Matched MeSH terms: Electron Transport Complex IV/genetics
Fulltext Homogeneous Nature of Malaysian Marine Fish Epinephelus fuscoguttatus (Perciformes; Serranidae): Evidence Based on Molecular Markers, Morphology and Fourier Transform Infrared Analysis

Nurdalila AA, Bunawan H, Kumar SV, Rodrigues KF, Baharum SN

Int J Mol Sci, 2015 Jul 02;16(7):14884-900.
PMID: 26147421 DOI: 10.3390/ijms160714884

Taxonomic confusion exists within the genus Epinephelus due to the lack of morphological specializations and the overwhelming number of species reported in several studies. The homogenous nature of the morphology has created confusion in the Malaysian Marine fish species Epinephelus fuscoguttatus and Epinephelus hexagonatus. In this study, the partial DNA sequence of the 16S gene and mitochondrial nucleotide sequences of two gene regions, Cytochrome Oxidase Subunit I and III were used to investigate the phylogenetic relationship between them. In the phylogenetic trees, E. fuscoguttatus was monophyletic with E. hexagonatus species and morphology examination shows that no significant differences were found in the morphometric features between these two taxa. This suggests that E. fuscoguttatus is not distinguishable from E. hexagonatus species, and that E. fuscoguttatus have been identified to be E. hexagonatus species is likely attributed to differences in environment and ability to camouflage themselves under certain conditions. Interestingly, this finding was also supported by Principal Component Analysis on Attenuated Total Reflectance-Fourier-transform Infrared (ATR-FTIR) data analysis. Molecular, morphological and meristic characteristics were combined with ATR-FTIR analysis used in this study offer new perspectives in fish species identification. To our knowledge, this is the first report of an extensive genetic population study of E. fuscoguttatus in Malaysia and this understanding will play an important role in informing genetic stock-specific strategies for the management and conservation of this highly valued fish.

Matched MeSH terms: Electron Transport Complex IV/genetics*
Morphological description and genetic analysis of a new black fly species (Diptera: Simuliidae) in the subgenus Asiosimulium from central Thailand

Srisuka W, Takaoka H, Taai K, Maleewong W, Aupalee K, Saeung A

Parasit Vectors, 2024 Sep 05;17(1):379.
PMID: 39238034 DOI: 10.1186/s13071-024-06441-z

BACKGROUND: Black flies are among the most medically and veterinary important insects, as adult females of certain species are the sole vector of Onchocerca volvulus. Here, a new black fly species belonging to the subgenus Asiosimulium Takaoka & Choochote, 2005, is described and formally named as Simulium (Asiosimulium) kittipati sp. nov.
METHODS: Pupae and larvae of black flies were collected from available substrates in the stream from central Thailand. Pupae were individually separated in plastic tubes and maintained until adult flies emerged. The emerged adult flies associated with their pupal exuviae and cocoon as well as mature larvae preserved in 85% ethanol were used to describe the new species based on an integrated approach of morphological examination and molecular analysis of the COI gene.
RESULTS: The new species is characterized in the female by the medium-long sensory vesicle with a medium-sized opening apically, scutum with three faint longitudinal vittae, and the ellipsoidal spermatheca; in the male by the number of upper-eye (large) facets in 20 vertical columns and 21 horizontal rows, hind basitarsus slender, nearly parallel-sided, and median sclerite much wider and upturned apically; in the pupa by the head and thoracic integument densely covered with tiny tubercles, and the pupal gill of arborescent type with 28-30 filaments; and in the larva by the postgenal cleft deep, nearly reaching the posterior margin of the hypostoma, and dark pigmented sheath of the subesophageal ganglion. The DNA barcode successfully differentiated the new species from its congeners with an interspecific genetic divergence of 1.74-18.72%, confirming the morphological identification that the species is a new member of the subgenus Asiosimulium. Phylogenetic analyses also indicated that the new species is genetically closely related to Simulium phurueaense Tangkawanit, Wongpakam & Pramual, 2018, further supporting its morphological classification.
CONCLUSIONS: This is the ninth species assigned to the subgenus Asiosimulium within the genus Simulium Latreille, 1802. Taxonomic notes and identification keys are given to distinguish this new species from the eight known species members in its same subgenus. Additionally, a distribution map of all species members in this subgenus occurring in Thailand and other countries is provided.

Matched MeSH terms: Electron Transport Complex IV/genetics
New host record and redescription of Amblyomma cordiferum nymphs and larvae infesting Malaysian house rats (Rattus rattus diardii) in Peninsular Malaysia, with molecular evidence of Rickettsia, Borrelia, and Bartonella

Kazim AR, Nasir DM, Tan TK, Yin VW, Noh AAM, Heo CC, et al.

Acta Trop, 2025 Jan;261:107496.
PMID: 39667694 DOI: 10.1016/j.actatropica.2024.107496

Nymphal and larval Amblyomma cordiferum ticks, a relatively rare species, were collected from the Malaysian house rat (Rattus rattus diardii) in Peninsular Malaysia. Redescription and molecular analysis of nymphs and larvae, based on the 12S rRNA, 16S rRNA, and COI genes, revealed divergence from A. cordiferum in Taiwan, suggesting that the Taiwanese tick specimens may represent a different taxon. Molecular analysis of the pathogens in these specimens revealed three sequences of Rickettsia closely related or identical to Rickettsia raoultii (99.71-100%), two sequences of relapsing fever Borrelia identical to Borrelia theileri, and four sequences of Bartonella identical to Bartonella phoceensis. This study also identifies a new host record for A. cordiferum in R. r. diardii and reports the first detection of Rickettsia, Borrelia, and Bartonella in this tick species.

Matched MeSH terms: Electron Transport Complex IV/genetics
Enhanced data on Stolephorus grandis and Stolephorus waitei (Teleostei: Clupeiformes: Engraulidae), two species endemic to the Sahul Shelf, western Pacific Ocean

Hata H, Wibowo K, Lavoué S, Pogonoski JJ, Appleyard SA, Motomura H

Zootaxa, 2024 Nov 13;5538(1):1-22.
PMID: 39645725 DOI: 10.11646/zootaxa.5538.1.1

Eighteen and 23 specimens of two species of the poorly known anchovies Stolephorus grandis Hata & Motomura, 2021b and Stolephorus waitei Jordan & Seale, 1926 (Clupeiformes: Engraulidae), respectively, are examined. This study presents their detailed morphological characters including fresh colorations along with their precise distributional ranges within the Sahul Shelf coastal region. The "barcode" regions of the mitochondrial cytochrome c oxidase subunit I (COI) gene were examined in four specimens of S. waitei and one specimen of S. grandis. Both species diverged by 10.6% and > 10.3% mean (uncorrected) genetic distances from each other and from any other species of Stolephorus, respectively. Stolephorus waitei, S. grandis, and Stolephorus nelsoni Wongratana, 1987 form a monophyletic group of species endemic to the Sahul Shelf region. Additionally, the role and evolution of double lines on the dorsum observed in several species of Stolephorus, including S. grandis, are discussed.

Matched MeSH terms: Electron Transport Complex IV/genetics
High-throughput terrestrial biodiversity assessments: mitochondrial metabarcoding, metagenomics or metatranscriptomics?

Wilson JJ, Brandon-Mong GJ, Gan HM, Sing KW

Mitochondrial DNA A DNA Mapp Seq Anal, 2019 01;30(1):60-67.
PMID: 29591722 DOI: 10.1080/24701394.2018.1455189

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.

Matched MeSH terms: Electron Transport Complex IV/genetics
Varroa jacobsoni (Acari: Varroidae) is more than one species

Anderson DL, Trueman JW

Exp Appl Acarol, 2000 Mar;24(3):165-89.
PMID: 11108385

Varroa jacobsoni was first described as a natural ectoparasitic mite of the Eastern honeybee (Apis cerana) throughout Asia. It later switched host to the Western honeybee (A. mellifera) and has now become a serious pest of that bee worldwide. The studies reported here on genotypic, phenotypic and reproductive variation among V. jacobsoni infesting A. cerana throughout Asia demonstrate that V. jacobsoni is a complex of at least two different species. In a new classification V. jacobsoni is here redefined as encompassing nine haplotypes (mites with distinct mtDNA CO-I gene sequences) that infest A. cerana in the Malaysia Indonesia region. Included is a Java haplotype, specimens of which were used to first describe V. jacobsoni at the beginning of this century. A new name, V. destructor n. sp., is given to six haplotypes that infest A. cerana on mainland Asia. Adult females of V. destructor are significantly larger and less spherical in shape than females of V. jacobsoni and they are also reproductively isolated from females of V. jacobsoni. The taxonomic positions of a further three unique haplotypes that infest A. cerana in the Philippines is uncertain and requires further study. Other studies reported here also show that only two of the 18 different haplotypes concealed within the complex of mites infesting A. cerana have become pests of A. mellifera worldwide. Both belong to V. destructor, and they are not V. jacobsoni. The most common is a Korea haplotype, so-called because it was also found parasitizing A. cerana in South Korea. It was identified on A. mellifera in Europe, the Middle East, Africa, Asia, and the Americas. Less common is a Japan/Thailand haplotype, so-called because it was also found parasitizing A. cerana in Japan and Thailand. It was identified on A. mellifera in Japan, Thailand and the Americas. Our results imply that the findings of past research on V. jacobsoni are applicable mostly to V. destructor. Our results will also influence quarantine protocols for bee mites, and may present new strategies for mite control.

Matched MeSH terms: Electron Transport Complex IV/genetics*
Geographical genetic structure within the human lung fluke, Paragonimus westermani, detected from DNA sequences

Blair D, Agatsuma T, Watanobe T, Okamoto M, Ito A

Parasitology, 1997 Oct;115 ( Pt 4):411-7.
PMID: 9364568

Nucleotide sequences were obtained for the second internal transcribed spacer of the ribosomal gene repeat and for part of the mitochondrial-cytochrome c oxidase subunit I gene from geographical isolates of Paragonimus westermani from Japan, China, Korea, Taiwan, the Philippines, peninsular Malaysia and Thailand. Sequences were obtained from several other species of Paragonimus for comparative purposes. Two groups were recognized within P. westermani: an NE group (China, Japan, Korea, Taiwan) which was relatively uniform and included both diploid and triploid forms, and a southern group (Malaysia, Thailand, Philippines), members of which were genetically distant from one another. According to both ITS2 and COI data, genetic distances among P. westermani isolates equalled or exceeded those between some distinct species of Paragonimus. The ITS2 sequences were conserved relative to COI sequences. Substitutions among the latter may be approaching saturation within the genus Paragonimus.

Matched MeSH terms: Electron Transport Complex IV/genetics
Parasite speciation within or between host species?--phylogenetic evidence from site-specific polystome monogeneans

Littlewood DT, Rohde K, Clough KA

Int J Parasitol, 1997 Nov;27(11):1289-97.
PMID: 9421713

Partial nuclear 28S ribosomal RNA and mitochondrial cytochrome c oxidase subunit I (COI) gene sequences (953 and 385 nucleotides, respectively) of one fish monogenean (outgroup) and six polystome monogeneans (four Polystomoides spp. from the oral cavities and urinary bladders of freshwater turtles in Australia and Malaya, two Neopolystoma spp. from the urinary bladder and conjunctival sac of a freshwater turtle in Australia) were used to examine the question of whether congeneric species infecting different sites in the same host species have speciated in that host by adapting to different sites, or whether species infecting a particular site in one host have given rise to species infecting the same site in different hosts. Results show unequivocally that congeneric species infecting the same site, even of host species belonging to different suborders and occurring on different continents, are more closely related than congeneric species infecting different sites of the same host species. This is interpreted as meaning that speciation has not occurred in one host. Morphological evolution of polystomes has been very slow: few differences between species and even genera have evolved over a period of at least 150 Myr, and this is matched by low substitution rates of nucleotides, and the ambiguous position of species of different genera, depending on whether COI or 28S rDNA sequences are used.

Matched MeSH terms: Electron Transport Complex IV/genetics
Fulltext Phylogeographic Evidence for 2 Genetically Distinct Zoonotic Plasmodium knowlesi Parasites, Malaysia

Yusof R, Ahmed MA, Jelip J, Ngian HU, Mustakim S, Hussin HM, et al.

Emerg Infect Dis, 2016 Aug;22(8):1371-80.
PMID: 27433965 DOI: 10.3201/eid2208.151885

Infections of humans with the zoonotic simian malaria parasite Plasmodium knowlesi occur throughout Southeast Asia, although most cases have occurred in Malaysia, where P. knowlesi is now the dominant malaria species. This apparently skewed distribution prompted an investigation of the phylogeography of this parasite in 2 geographically separated regions of Malaysia, Peninsular Malaysia and Malaysian Borneo. We investigated samples collected from humans and macaques in these regions. Haplotype network analyses of sequences from 2 P. knowlesi genes, type A small subunit ribosomal 18S RNA and cytochrome c oxidase subunit I, showed 2 genetically distinct divergent clusters, 1 from each of the 2 regions of Malaysia. We propose that these parasites represent 2 distinct P. knowlesi types that independently became zoonotic. These types would have evolved after the sea-level rise at the end of the last ice age, which separated Malaysian Borneo from Peninsular Malaysia.

Matched MeSH terms: Electron Transport Complex IV/genetics
Cytochrome c oxidase subunit I haplotype diversity of Angiostrongylus cantonensis (Nematoda: Angiostrongylidae)

Eamsobhana P, Song SL, Yong HS, Prasartvit A, Boonyong S, Tungtrongchitr A

Acta Trop, 2017 Jul;171:141-145.
PMID: 28347653 DOI: 10.1016/j.actatropica.2017.03.020

The rat lungworm Angiostrongylus cantonensis is a food-borne zoonotic parasite of public health importance worldwide. It is the primary etiologic agent of eosinophilic meningitis and eosinophilic meningoencephalitis in humans in many countries. It is highly endemic in Thailand especially in the northeast region. In this study, A. cantonensis adult worms recovered from the lungs of wild rats in different geographical regions/provinces in Thailand were used to determine their haplotype by means of the mitochondrial partial cytochrome c oxidase subunit I (COI) gene sequence. The results revealed three additional COI haplotypes of A. cantonensis. The geographical isolates of A. cantonensis from Thailand and other countries formed a monophyletic clade distinct from the closely related A. malaysiensis. In the present study, distinct haplotypes were identified in seven regions of Thailand - AC10 in Phitsanulok (northern region), AC11 in Nakhon Phanom (northeastern region), AC15 in Trat (eastern region), AC16 in Chantaburi (eastern region), AC4 in Samut Prakan (central region), AC14 in Kanchanaburi (western region), and AC13 in Ranong (southern region). Phylogenetic analysis revealed that these haplotypes formed distinct lineages. In general, the COI sequences did not differentiate the worldwide geographical isolates of A. cantonensis. This study has further confirmed the presence of COI haplotype diversity in various geographical isolates of A. cantonensis. The COI gene sequence will be a suitable marker for studying population structure, phylogeography and genetic diversity of the rat lungworm.

Matched MeSH terms: Electron Transport Complex IV/genetics*
Fulltext Genetic diversity, population structure and historical demography of the two-spined yellowtail stargazer (Uranoscopus cognatus)

Mohd Yusoff NIS, Mat Jaafar TNA, Vilasri V, Mohd Nor SA, Seah YG, Habib A, et al.

Sci Rep, 2021 Jun 25;11(1):13357.
PMID: 34172804 DOI: 10.1038/s41598-021-92905-6

Benthic species, though ecologically important, are vulnerable to genetic loss and population size reduction due to impacts from fishing trawls. An assessment of genetic diversity and population structure is therefore needed to assist in a resource management program. To address this issue, the two-spined yellowtail stargazer (Uranoscopus cognatus) was collected within selected locations in the Indo-West Pacific (IWP). The partial mitochondrial DNA cytochrome c oxidase subunit 1 and the nuclear DNA recombination activating gene 1 were sequenced. Genetic diversity analyses revealed that the populations were moderately to highly diversified (haplotype diversity, H = 0.490-0.900, nucleotide diversity, π = 0.0010-0.0034) except sampling station (ST) 1 and 14. The low diversity level, however was apparent only in the matrilineal marker (H = 0.118-0.216; π = 0.0004-0.0008), possibly due to stochastic factors or anthropogenic stressors. Population structure analyses revealed a retention of ancestral polymorphism that was likely due to incomplete lineage sorting in U. cognatus, and prolonged vicariance by the Indo-Pacific Barrier has partitioned them into separate stock units. Population segregation was also shown by the phenotypic divergence in allopatric populations, regarding the premaxillary protrusion, which is possibly associated with the mechanism for upper jaw movement in biomechanical feeding approaches. The moderate genetic diversity estimated for each region, in addition to past population expansion events, indicated that U. cognatus within the IWP was still healthy and abundant (except in ST1 and 14), and two stock units were identified to be subjected to a specific resource management program.

Matched MeSH terms: Electron Transport Complex IV/genetics
Fulltext Sequence analysis on the mitochondrial COXI gene of recent clinical isolates of Plasmodium knowlesi in Klang Valley, peninsular Malaysia

Fong MY, Lau YL, Chin LC, Al-Mekhlafi AM

Trop Biomed, 2011 Aug;28(2):457-63.
PMID: 22041769

The cytochrome oxidase subunit I (COXI) gene sequences of three recent (2007-2008) clinical Plasmodium knowlesi isolates from Klang Valley, peninsular Malaysia, were determined and compared with those of older (1960's) peninsular Malaysia, recent isolates from Sarawak (on Borneo Island), and an isolate from Thailand. Multiple alignment of the sequences showed that the three clinical isolates were more similar to the older peninsular Malaysia isolates than to those from Sarawak and Thailand. Phylogenetic tree based on the COXI sequences revealed three distinct clusters of P. knowlesi. The first cluster consisted of isolates from peninsular Malaysia, the second consisted of Sarawak isolates and the third composed of the Thailand isolate. The findings of this study highlight the usefulness of mitochondrial COXI gene as a suitable marker for phylogeographic studies of P. knowlesi.

Matched MeSH terms: Electron Transport Complex IV/genetics*
Acanthocheilonema delicata n. sp. (Nematoda: Filarioidea) from Japanese badgers (Meles anakuma): description, molecular identification, and Wolbachia screening

Uni S, Bain O, Suzuki K, Agatsuma T, Harada M, Motokawa M, et al.

Parasitol Int, 2013 Feb;62(1):14-23.
PMID: 22926421 DOI: 10.1016/j.parint.2012.08.004

Acanthocheilonema delicata n. sp. (Filarioidea: Onchocercidae: Onchocercinae) is described based on adult filarioids and microfilariae obtained from subcutaneous connective tissues and skin, respectively, of Japanese badgers (Meles anakuma) in Wakayama Prefecture, Japan. No endemic species of the genus had been found in Japan. Recently, some filarioids (e.g., Acanthocheilonema reconditum, Dirofilaria spp., and Onchocerca spp.) have come to light as causative agents of zoonosis worldwide. The new species was readily distinguished from its congeners by morphologic characteristics such as body length, body width, esophagus length, spicule length, and the length of microfilariae. Based on the molecular data of the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene, A. delicata n. sp. was included in the clade of the genus Acanthocheilonema but differed from two other congeneric species available for study, A. viteae and A. reconditum. Acanthocheilonema delicata n. sp. did not harbor Wolbachia. It is likely that the fauna of filarioids from mammals on the Japanese islands is characterized by a high level of endemicity.

Matched MeSH terms: Electron Transport Complex IV/genetics

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