The occurrence of Suidasia medanensis (= S. pontifica) mites in Malaysian house dust was first reported in 1984. The taxonomy of this storage mite is, however, quite confusing. Therefore, we need an accurate identification to resolve morphological problems due to its minute size and some overlapping characters between species. The purpose of this study was to demonstrate the application of partial mitochondrial cytochrome c oxidase subunit I (COI) sequences for the identification of S. medanensis by PCR. Identity of the mite was first determined by observing morphological characters under a light microscope. Genomic DNA of S. medanensis mites was successfully extracted prior to PCR and DNA sequencing using COI universal primers. The length of the COI sequences obtained was 378 bp. BLAST analysis of amplicon sequences showed that local S. medanensis COI region had 99% maximum identity with S. medanensis nucleotide sequence (AY525568) available in the GenBank. As the phylogenetic tree generated indicated, COI sequences from this study were clustered with S. medanensis from Korea and the UK in one major clade, supported with high bootstrap value (> 85%). Results of the phylogenetic analysis of this COI gene were congruent with the morphological identification and provided strong support for a single clade of local S. medanensis.
Matched MeSH terms: Electron Transport Complex IV/analysis
The proboscis monkey, Nasalis larvatus, is an endemic species to the island of Borneo. It is listed in the IUCN Red List as Endangered with a decreasing population trend. Nevertheless, biological information, especially on the genetic diversity of the species, is still incomplete. Its fragmented distribution poses difficulties in gathering genetic samples along with its widespread distribution across Borneo. This study aims to determine the genetic variation and structure of N. larvatus with an emphasis on Malaysian Borneo populations to elucidate its gene flow. The genetic variation and structure of N. larvatus were examined using 50 sequences of the 1,434-bp cytochrome oxidase subunit I (COI) gene region of mitochondrial DNA. The COI sequences revealed low genetic variation among N. larvatus populations in Malaysian Borneo. This low genetic variability could be the result of inbreeding pressure that may have occurred due to the absence of population expansion in this species over the last 30,000 years. This is supported in our analysis of molecular variance, which showed that groups of N. larvatus are significantly differentiated possibly due to natural geographic barriers. This study provides baseline information on the genetic diversity among proboscis monkey populations in Borneo for the future genetic assessment of the species.
Matched MeSH terms: Electron Transport Complex IV/analysis
Analyses of the mitochondrial cox1, the nuclear-encoded large subunit (LSU), and the internal transcribed spacer 2 (ITS2) RNA coding region of Pseudo-nitzschia revealed that the P. pseudodelicatissima complex can be phylogenetically grouped into three distinct clades (Groups I-III), while the P. delicatissima complex forms another distinct clade (Group IV) in both the LSU and ITS2 phylogenetic trees. It was elucidated that comprehensive taxon sampling (sampling of sequences), selection of appropriate target genes and outgroup, and alignment strategies influenced the phylogenetic accuracy. Based on the genetic divergence, ITS2 resulted in the most resolved trees, followed by cox1 and LSU. The morphological characters available for Pseudo-nitzschia, although limited in number, were overall in agreement with the phylogenies when mapped onto the ITS2 tree. Information on the presence/absence of a central nodule, number of rows of poroids in each stria, and of sectors dividing the poroids mapped onto the ITS2 tree revealed the evolution of the recently diverged species. The morphologically based species complexes showed evolutionary relevance in agreement with molecular phylogeny inferred from ITS2 sequence-structure data. The data set of the hypervariable region of ITS2 improved the phylogenetic inference compared to the cox1 and LSU data sets. The taxonomic status of P. cuspidata and P. pseudodelicatissima requires further elucidation.
Matched MeSH terms: Electron Transport Complex IV/analysis
A new black fly species, Simulium haiduanense Takaoka, Low & Huang (Diptera: Simuliidae), is described on the basis of females, males, pupae, and mature larvae from Taiwan. This new species is placed in the Simulium argentipes species-group of the subgenus Simulium (Diptera: Simuliidae) and is characterized by the yellowish female legs, ovipositor valves rounded apically and with its inner margin concave, claw with a small subbasal tooth, male style without a basal protuberance, pupal gill with eight filaments, corbicular cocoon, and larval abdomen lacking paired protuberances. It represents the first record of the S. argentipes species-group from Taiwan. Taxonomic notes are given to separate this new species from all eight species in the same species-group. The phylogenetic relationships of this new species with four related species are presented.
Matched MeSH terms: Electron Transport Complex IV/analysis
Forensic entomology applies knowledge about insects associated with decedent in crime scene investigation. It is possible to calculate a minimum postmortem interval (PMI) by determining the age and species of the oldest blow fly larvae feeding on decedent. This study was conducted in Malaysia to identify maggot specimens collected during crime scene investigations. The usefulness of the molecular and morphological approach in species identifications was evaluated in 10 morphologically identified blow fly larvae sampled from 10 different crime scenes in Malaysia. The molecular identification method involved the sequencing of a total length of 2.2 kilo base pairs encompassing the 'barcode' fragments of the mitochondrial cytochrome oxidase I (COI), cytochrome oxidase II (COII) and t-RNA leucine genes. Phylogenetic analyses confirmed the presence of Chrysomya megacephala, Chrysomya rufifacies and Chrysomya nigripes. In addition, one unidentified blow fly species was found based on phylogenetic tree analysis.
Matched MeSH terms: Electron Transport Complex IV/analysis