Displaying publications 281 - 300 of 660 in total

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  1. The exchange of water and energy between a tropical peat forest and the atmosphere: Seasonal trends and comparison against other tropical rainforests
    Tang ACI, Stoy PC, Hirata R, Musin KK, Aeries EB, Wenceslaus J, et al.
    Sci Total Environ, 2019 Sep 15;683:166-174.
    PMID: 31132697 DOI: 10.1016/j.scitotenv.2019.05.217
    Tropical rainforests control the exchange of water and energy between the land surface and the atmosphere near the equator and thus play an important role in the global climate system. Measurements of latent (LE) and sensible heat exchange (H) have not been synthesized across global tropical rainforests to date, which can help place observations from individual tropical forests in a global context. We measured LE and H for four years in a tropical peat forest ecosystem in Sarawak, Malaysian Borneo using eddy covariance, and hypothesize that the study ecosystem will exhibit less seasonal variability in turbulent fluxes than other tropical ecosystems as soil water is not expected to be limiting in a tropical forested wetland. LE and H show little variability across seasons in the study ecosystem, with LE values on the order of 11 MJ m-2 day and H on the order of 3 MJ m-2 day-1. Annual evapotranspiration (ET) did not differ among years and averaged 1579 ± 47 mm year-1. LE exceeded characteristic values from other tropical rainforest ecosystems in the FLUXNET2015 database with the exception of GF-Guy near coastal French Guyana, which averaged 8-11 MJ m-2 day-1. The Bowen ratio (Bo) in tropical rainforests in the FLUXNET2015 database either exhibited little seasonal trend, one seasonal peak, or two peaks. Volumetric water content (VWC) and VPD explained a trivial amount of the variability of LE and Bo in some of the tropical rainforests including the study ecosystem, but were strong controls in others, suggesting differences in stomatal regulation and/or the partitioning between evaporation and transpiration. Results demonstrate important differences in the seasonal patterns in water and energy exchange across different tropical rainforest ecosystems that need to be understood to quantify how ongoing changes in tropical rainforest extent will impact the global climate system.
    Matched MeSH terms: Borneo
  2. Vocal apparatus structure of the Sarawak frogs (Amphibia: Anura: Ranidae)
    Ramlah Zainudin, Elvy Quatrin Deka, Lela Su’ut, Hasnizam Abdul Wahid
    Sains Malaysiana, 2015;44:1289-1299.
    Studies have shown that some characters, such as morphological, biochemical and behavioural characteristics were shared among con-specifics of closely related frog species. It is hypothesized that closely related frogs would have similar vocal apparatus structure to produce similar call characteristics, in order to be recognized by con-specifics. The vocal apparatus structures of the frogs from Ranidae were, thus, investigated and calls were recorded from various locations in Sarawak, Borneo. The vocal apparatus was sliced and stained using haematoxylin and eosin staining method. The prepared slides were scanned using Dotslide System Olympus BX51. Captured images were further measured using Microscope Olympus BX51. The results showed that the vocal apparatus structure of ranids in Sarawak differed in length between pulvinar vocale and posterior margin (pvpm) or known as vocal cord stricter. This character was deemed to be the most significant character to discriminate the Sarawak ranids. It is suggested that histological analysis is also a good method for study of phenotypic variation of frog species, as shown by the vocal apparatus structure of the anurans. This study provides an alternative method to differentiate taxonomic identity among frog species.
    Matched MeSH terms: Borneo
  3. Conservation gap analysis of dipterocarp hotspots in Sarawak using GIS, remote sensing and herbarium data
    Stephen P. Teo, Paul P.K. Chai, Mui-How Phua
    Sains Malaysiana, 2013;42:1237-1246.
    Dipterocarpaceae is the dominant tree family in the tropical rain forests of Southeast Asia. Borneo is the centre of diversity for the dipterocarps. Identification of hotspots is important for forest and biodiversity conservation efforts. Species Occurrence Models (SOMs) were generated for all 247 species of dipterocarps recorded in Sarawak using herbarium occurrence data and based on the best model selected. The species occurrence density map for each genus and category (endemic and non endemic) was generated by overlaying the SOMs of all species in each genus or category. The species occurrence density maps were analyzed with land cover map from Landsat 7-EMT+ images and protected forest areas for identifying hotspots for conservation in Sarawak. Overlaying the SOM maps revealed that areas in central Sarawak and the southwest region (northwest Borneo around Kuching) are the main hotspots of dipterocarp diversity in Sarawak while the coastal lowland areas in the lower Rejang and Baram River which are mainly peat swamp forest are poorer in species occurrence density. In terms of endemism, as with dipterocarp diversity, the mixed diptercarp forest of central Sarawak is also the most important hotspot. Gap analysis revealed that most protected forest areas are in southwest Sarawak (Bako, Kubah, Tanjung Datu and Gunung Gading National Parks) and in the northern part of Sarawak (Niah, Lambir Hills and Mt Mulu National Parks). This leaves the hotspot in the central part of Sarawak least protected. Protected areas only cover between 2 and 4% of the total areas for the different hotspots (75% species density) while majority of the hotspots that are still forested are outside the protected areas.
    Matched MeSH terms: Borneo
  4. New lymantriidae record for Peninsular Malaysia: Toxoproctis Hemibathes (Swinhoe)
    Norela Sulaiman, Mohd Faizal Rus Rzerli, Maimon Abdullah
    Sains Malaysiana, 2011;40:1179-1186.
    This paper reports on a new record of the itch moth from the family Lymantriidae, Toxoproctis hemibathes (Swinhoe), for Peninsular Malaysia. The islands of Sumatera and Borneo are known to be within the geographical range of Lymantriidae, their habitat preference being the wetland and coastal forests. Our study showed that this species can also erupt in large numbers in specific locations in the southern parts of Peninsular Malaysia and thus, our finding is considered a new record for T. hemibathes (Swinhoe). This specimens were collected using portable ultra violet (UV) light trap during a population outbreak of this species in the Labis District of Johore.
    Matched MeSH terms: Borneo
  5. Fulltext Termites can decompose more than half of deadwood in tropical rainforest
    Griffiths HM, Ashton LA, Evans TA, Parr CL, Eggleton P
    Curr Biol, 2019 02 18;29(4):R118-R119.
    PMID: 30779897 DOI: 10.1016/j.cub.2019.01.012
    Termite-mediated decomposition is an important, but often overlooked, component of the carbon cycle. Using a large-scale suppression experiment in Borneo, Griffiths et al. found that termites contribute between 58 and 64% of mass loss from dead wood.
    Matched MeSH terms: Borneo
  6. Ancyronyx clisteri, a new spider riffle beetle species from Borneo, redescription of A. sarawacensis Jäch including a description of the larva and new distribution data for A. procerus Jäch using DNA barcodes (Coleoptera, Elmidae)
    Kodada J, Jäch MA, Freitag H, Čiamporová-Zaťovičová Z, Goffová K, Selnekovič D, et al.
    Zookeys, 2020;912:25-64.
    PMID: 32123499 DOI: 10.3897/zookeys.912.47796
    Ancyronyx clisterisp. nov. (Coleoptera, Elmidae) a new spider riffle beetle discovered from northern Borneo (Brunei; Sabah and Sarawak, Malaysia) and the larva of Ancyronyx sarawacensis Jäch are described. Illustrations of the habitus and diagnostic characters of the new species and the similar and highly variable A. sarawacensis are presented. Differences to closely related species, based on DNA barcodes and morphological characters, are discussed. Association of the larva and the imago of A. sarawacensis, and the occurrence of Ancyronyx procerus Jäch in Peninsular Malaysia and Sabah are confirmed by using COI mtDNA sequences.
    Matched MeSH terms: Borneo
  7. Bacterial community diversity in the rhizosphere of nickel hyperaccumulator plant species from Borneo Island (Malaysia)
    Lopez S, van der Ent A, Sumail S, Sugau JB, Buang MM, Amin Z, et al.
    Environ Microbiol, 2020 04;22(4):1649-1665.
    PMID: 32128926 DOI: 10.1111/1462-2920.14970
    The Island of Borneo is a major biodiversity hotspot, and in the Malaysian state of Sabah, ultramafic soils are extensive and home to more than 31 endemic nickel hyperaccumulator plants. The aim of this study was to characterize the structure and the diversity of the rhizosphere bacterial communities of several of these nickel hyperaccumulator plants and factors that affect these bacterial communities in Sabah. The most abundant phyla were Proteobacteria, Acidobacteria and Actinobacteria. At family level, Burkholderiaceae and Xanthobacteraceae (Proteobacteria phylum) were the most abundant families in the hyperaccumulator rhizospheres. Redundancy analysis based on soil chemical analyses and relative abundances of the major bacterial phyla showed that abiotic factors of the studied sites drove the bacterial diversity. For all R. aff. bengalensis rhizosphere soil samples, irrespective of studied site, the bacterial diversity was similar. Moreover, the Saprospiraceae family showed a high representativeness in the R. aff. bengalensis rhizosphere soils and was linked with the nickel availability in soils. The ability of R. aff. bengalensis to concentrate nickel in its rhizosphere appears to be the major factor driving the rhizobacterial community diversity unlike for other hyperaccumulator species.
    Matched MeSH terms: Borneo
  8. Fulltext A new species of Clavicornaltica (Coleoptera: Chrysomelidae), discovered and described on a field course to Kuala Belalong, Brunei
    Schilthuizen M, Berenyi AEA, Limin A, Brahim A, Cicuzza D, Eales AJ, et al.
    Biodivers Data J, 2019.
    PMID: 30740026 DOI: 10.3897/BDJ.7.e32555
    Background: Clavicornaltica is a genus of very small flea beetles living in the leaf litter layer of Asian forests, easily sampled with Winkler extraction. The genus is presumably very rich in species, but their taxonomy is hampered by their small size and morphological uniformity.

    New information: On a 'taxon expedition'-style field course at Kuala Belalong Field Studies Centre in Brunei Darussalam (Borneo), a new species, Clavicornaltica belalongensis n. sp., was discovered and taxonomically treated by the course participants. We also present the first DNA barcodes for the genus.

    Matched MeSH terms: Borneo
  9. Bornean orangutans: primary forest in Danum Valley and rehabilitation program on Orangutan Island
    Matsuzawa T
    Primates, 2019 11;60(6):477-483.
    PMID: 31679101 DOI: 10.1007/s10329-019-00771-8
    Matched MeSH terms: Borneo
  10. Fulltext The Pictorial Fit-Frail Scale: Developing a Visual Scale to Assess Frailty
    Theou O, Andrew M, Ahip SS, Squires E, McGarrigle L, Blodgett JM, et al.
    Can Geriatr J, 2019 Jun;22(2):64-74.
    PMID: 31258829 DOI: 10.5770/cgj.22.357
    Background: Standardized frailty assessments are needed for early identification and treatment. We aimed to develop a frailty scale using visual images, the Pictorial Fit-Frail Scale (PFFS), and to examine its feasibility and content validity.

    Methods: In Phase 1, a multidisciplinary team identified domains for measurement, operationalized impairment levels, and reviewed visual languages for the scale. In Phase 2, feedback was sought from health professionals and the general public. In Phase 3, 366 participants completed preliminary testing on the revised draft, including 162 UK paramedics, and rated the scale on feasibility and usability. In Phase 4, following translation into Malay, the final prototype was tested in 95 participants in Peninsular Malaysia and Borneo.

    Results: The final scale incorporated 14 domains, each conceptualized with 3-6 response levels. All domains were rated as "understood well" by most participants (range 64-94%). Percentage agreement with positive statements regarding appearance, feasibility, and usefulness ranged from 66% to 95%. Overall feedback from health-care professionals supported its content validity.

    Conclusions: The PFFS is comprehensive, feasible, and appears generalizable across countries, and has face and content validity. Investigation into the reliability and predictive validity of the scale is currently underway.

    Matched MeSH terms: Borneo
  11. Whipworms of south-east Asian rodents are distinct from Trichuris muris
    Ribas A, Wells K, Morand S, Chaisiri K, Agatsuma T, Lakim MB, et al.
    Parasitol Int, 2020 Aug;77:102128.
    PMID: 32330535 DOI: 10.1016/j.parint.2020.102128
    The whipworm Trichuris muris is known to be associated with various rodent species in the northern hemisphere, but the species identity of whipworm infecting rodents in the Oriental region remains largely unknown. We collected Trichuris of Muridae rodents in mainland and insular Southeast Asia between 2008 and 2015 and used molecular and morphological approaches to identify the systematic position of new specimens. We discovered two new species that were clearly distinct from T. muris, both in terms of molecular phylogenetic clustering and morphological features, with one species found in Thailand and another one in Borneo. We named the new species from Thailand as Trichuris cossoni and the species from Borneo as Trichuris arrizabalagai. Molecular phylogeny using internal transcribed spacer region (ITS1-5.8S-ITS2) showed a divergence between T. arrizabalagai n. sp., T. cossoni n. sp. and T. muris. Our findings of phylogeographically distinct Trichuris species despite some globally distributed host species requires further research into the distribution of different species, previously assumed to belong to T. muris, which has particular relevance for using these species as laboratory model organisms.
    Matched MeSH terms: Borneo
  12. Fulltext High proportion of norovirus infection and predominance of GII.3 [P12] genotype among the children younger than 5 in Sabah, Malaysian Borneo
    John JL, Mori D, Amit LN, Mosiun AK, Chin AZ, Ahmed K
    J Clin Virol, 2021 10;143:104968.
    PMID: 34509928 DOI: 10.1016/j.jcv.2021.104968
    Globally, norovirus (NoV) has become one of the important causes of acute gastroenteritis (AGE) in children. It is responsible for death of children younger than 5 years in developing countries. Although there is limited information and the rate of child mortality caused by diarrhea is low in Malaysia, the burden of diarrhea is high, especially in Sabah. NoV GI, GII and GIV genogroups are known to infect humans, and GII.4 is the predominant genotype distributed worldwide. Better understanding of the etiology of NoV will help to inform policies for prevention and control. The aim of this study was to determine the burden and genotype distribution of NoV in children younger than 5 years with AGE who attended health-care facilities in Sabah, Malaysia. Diarrhea stool samples were collected from 299 children with AGE and NoV was detected by amplifying the capsid and RNA-dependent RNA polymerase gene and reverse transcription-polymerase chain reaction (RT-PCR) analysis. Nucleotide sequencing of the amplicons was used for genotypes and phylogenetic analyses . NoV-positive stool samples were found in 17.7% (53/299) among which 13/53 (24.5%), 38/53 (71.7%), and 2/53 (3.8%) identified as NoV GI, GII and combination of GI and GII, respectively. The most common genotypes were GII.3 [P12] (80%) followed by GII.6 [P7] (13.3%), and GII.17 [P17] (6.7%). In the phylogenetic tree, all Sabahan NoV samples were shown to share ancestry with their respective genotype from predominantly East Asian countries and to some extent Australia and Europe. However, the Sabahan strains formed independent clusters with significant bootstrap values, indicating a clonal spread after the strains had entered Sabah.
    Matched MeSH terms: Borneo
  13. Femur associated with the Deep Skull from the West Mouth of the Niah Caves (Sarawak, Malaysia)
    Curnoe D, Datan I, Goh HM, Sauffi MS
    J Hum Evol, 2019 02;127:133-148.
    PMID: 30777354 DOI: 10.1016/j.jhevol.2018.12.008
    The skeletal remains of Pleistocene anatomically modern humans are rare in island Southeast Asia. Moreover, continuing doubts over the dating of most of these finds has left the arrival time for the region's earliest inhabitants an open question. The unique biogeography of island Southeast Asia also raises questions about the physical and cultural adaptations of early anatomically modern humans, especially within the setting of rainforest inhabitation. Within this context the Deep Skull from the West Mouth of the Niah Caves continues to figure prominently owing to its relative completeness and the greater certainty surrounding its geological age. Recovered along with this partial cranium in 1958 were several postcranial bones including a partial femur which until now has received little attention. Here we provide a description and undertake a comparison of the Deep Skull femur finding it to be very small in all of its cross-sectional dimensions. We note a number of size and shape similarities to the femora of Indigenous Southeast Asians, especially Aeta people from the Philippines. We estimate its stature to have been roughly 145-146 cm and body mass around 35 kg, confirming similarities to Aeta females. Its extreme gracility indicated by low values for a range of biomechanical parameters taken midshaft meets expectations for a very small (female) Paleolithic East Asian. Interestingly, the second moment of area about the mediolateral axis is enlarged relative to the second moment of area about the anteroposterior axis, which could potentially signal a difference in activity levels or lifestyle compared with other Paleolithic femora. However, it might also be the result of sexual dimorphism in these parameters as well as possibly reflecting changes associated with aging.
    Matched MeSH terms: Borneo
  14. Fulltext Temporal activity patterns suggesting niche partitioning of sympatric carnivores in Borneo, Malaysia
    Nakabayashi M, Kanamori T, Matsukawa A, Tangah J, Tuuga A, Malim PT, et al.
    Sci Rep, 2021 10 06;11(1):19819.
    PMID: 34615956 DOI: 10.1038/s41598-021-99341-6
    To propose proper conservation measures and to elucidate coexistence mechanisms of sympatric carnivore species, we assessed temporal activity patterns of the sympatric carnivore species using 37,379 photos collected for more than 3 years at three study sites in Borneo. We categorized activity patterns of nine carnivore species (one bear, three civets, two felids, one skunk, one mustelid, one linsang) by calculating the photo-capturing proportions at each time period (day, night, twilight). We then evaluated temporal activity overlaps by calculating the overlap coefficients. We identified six nocturnal (three civets, one felid, one skunk, one linsang), two diurnal (one felid, one mustelid), and one cathemeral (bear) species. Temporal activity overlaps were high among the nocturnal species. The two felid species possessing morphological and ecological similarities exhibited clear temporal niche segregation, but the three civet species with similar morphology and ecology did not. Broad dietary breadth may compensate for the high temporal niche overlaps among the nocturnal species. Despite the high species richness of Bornean carnivores, almost half are threatened with extinction. By comparing individual radio-tracking and our data, we propose that a long-term study of at least 2 or 3 years is necessary to understand animals' temporal activity patterns, especially for sun bears and civets, by camera-trapping and to establish effective protection measures.
    Matched MeSH terms: Borneo
  15. Fulltext Long-term carbon sink in Borneo's forests halted by drought and vulnerable to edge effects
    Qie L, Lewis SL, Sullivan MJP, Lopez-Gonzalez G, Pickavance GC, Sunderland T, et al.
    Nat Commun, 2017 12 19;8(1):1966.
    PMID: 29259276 DOI: 10.1038/s41467-017-01997-0
    Less than half of anthropogenic carbon dioxide emissions remain in the atmosphere. While carbon balance models imply large carbon uptake in tropical forests, direct on-the-ground observations are still lacking in Southeast Asia. Here, using long-term plot monitoring records of up to half a century, we find that intact forests in Borneo gained 0.43 Mg C ha-1 per year (95% CI 0.14-0.72, mean period 1988-2010) above-ground live biomass. These results closely match those from African and Amazonian plot networks, suggesting that the world's remaining intact tropical forests are now en masse out-of-equilibrium. Although both pan-tropical and long-term, the sink in remaining intact forests appears vulnerable to climate and land use changes. Across Borneo the 1997-1998 El Niño drought temporarily halted the carbon sink by increasing tree mortality, while fragmentation persistently offset the sink and turned many edge-affected forests into a carbon source to the atmosphere.
    Matched MeSH terms: Borneo
  16. Fulltext Biodiversity conservation values of fragmented communally reserved forests, managed by indigenous people, in a human-modified landscape in Borneo
    Takeuchi Y, Soda R, Diway B, Kuda TA, Nakagawa M, Nagamasu H, et al.
    PLoS One, 2017;12(11):e0187273.
    PMID: 29186138 DOI: 10.1371/journal.pone.0187273
    This study explored the conservation values of communally reserved forests (CRFs), which local indigenous communities deliberately preserve within their area of shifting cultivation. In the current landscape of rural Borneo, CRFs are the only option for conservation because other forested areas have already been logged or transformed into plantations. By analyzing their alpha and beta diversity, we investigated how these forests can contribute to restore regional biodiversity. Although CRFs were fragmented and some had been disturbed in the past, their tree species diversity was high and equivalent to that of primary forests. The species composition of intact forests and forests disturbed in the past did not differ clearly, which indicates that past logging was not intensive. All CRFs contained unique and endangered species, which are on the IUCN Red List, Sarawak protected plants, or both. On the other hand, the forest size structure differed between disturbed and intact CRFs, with the disturbed CRFs consisting of relatively smaller trees. Although the beta diversity among CRFs was also high, we found a high contribution of species replacement (turnover), but not of richness difference, in the total beta diversity. This suggests that all CRFs have a conservation value for restoring the overall regional biodiversity. Therefore, for maintaining the regional species diversity and endangered species, it would be suitable to design a conservation target into all CRFs.
    Matched MeSH terms: Borneo
  17. Fulltext Biology of Incidental Catch Sea Star Stellaster childreni Gray, 1840 (Echinodermata: Asteroidea), from Malaysian Borneo Exclusive Economic Zone
    Hassan R, Lee SY, Morni WZW
    ScientificWorldJournal, 2017;2017:1489360.
    PMID: 28695188 DOI: 10.1155/2017/1489360
    Sea star (class Asteroidea, phylum Echinodermata) is one of the most successful marine organisms inhabiting a wide range of habitats. As one of the key stone species, sea stars are responsible for maintaining much of the local diversity of species within certain communities. Malaysian Exclusive Economic Zone (EEZ) Resource Survey had been carried out from 16th Aug to 6th Nov 2015 and one of the invertebrate by-catch organisms is sea star Stellaster childreni Gray, 1840. This study documents morphological characters and diet of the sea star, besides providing brief descriptions of the habitats based on particle size analysis and vessel log data sheet. A total of 217 individuals had been examined throughout this study. Fragments of flora and fauna were found in the gut including Mollusca (gastropod, bivalves, and scaphopods), sponge seagrass, and seaweed as well as benthic Foraminifera. Stellaster childreni were found at depth of 45 m to 185 m in the South China Sea off Sarawak Malaysia, with various sea bottom substrata. Approximately 41% of S. childreni were found at a mixture of sandy and muddy substratum, followed by mixture of sandy and coral (19.3%), muddy substratum (17.5%), coral substratum (11.5%), and sandy areas (10.6%). The widely distributed sea star on different types of sea beds suggested healthy deep sea ecosystem; thus Malaysia should explore further potential fisheries resources in the EEZ off Sarawak coast.
    Matched MeSH terms: Borneo
  18. Review of the genus Anipocregyes Breuning, 1939 with two new species from Borneo (Coleoptera, Cerambycidae, Lamiinae, Mesosini)
    Yamasako J, Makihara H
    Zootaxa, 2017 Apr 07;4250(5):461-474.
    PMID: 28610002 DOI: 10.11646/zootaxa.4250.5.4
    The genus Anipocregyes Breuning, 1939 is reviewed. Cristipocregyes rondoni Breuning, 1965, Metipocregyes rondoni Breuning, 1965, and Mesosa (Perimesosa) seminivea Breuning, 1965 are transferred to the genus Anipocregyes, and Setomesosa rondoni Breuning, 1968 is synonymized with A. seminivea comb. nov. As a result, two genera, Cristipocregyes Breuning, 1965 and Setomesosa Breuning, 1968, are synonymized with Anipocregyes. Metipocregyes rondoni Breuning, 1965 becomes a secondary homonym and Anipocregyes albifrons nom. nov. is proposed as a replacement name. Anipocregyes kawakamii sp. nov. and A. wakabayashii sp. nov. are described from Borneo. All the seven known species of Anipocregyes are illustrated with their male genitalia (except for A. laosensis) and a key to the species is provided.
    Matched MeSH terms: Borneo
  19. Revision of the Genus Leptogomphus Selys in Borneo, including gene trees and a two marker molecular phylogeny (Odonata: Anisoptera: Gomphidae)
    Dow RA, Stokvis F, Ngiam RWJ
    Zootaxa, 2017 Nov 29;4358(2):201-257.
    PMID: 29245467 DOI: 10.11646/zootaxa.4358.2.1
    The Bornean members of the genus Leptogomphus Selys are revised. Two new species are described: Leptogomphus schieli sp. nov. (holotype ♂, Gunung Penrissen, Kuching Division, Sarawak, Malaysia, to be deposited in BMNH) and Leptogomphus sii sp. nov. (holotype ♂, Sungai Sii, upper Baram, Miri Division, Sarawak, Malaysia, in RMNH). Leptogomphus mariae Lieftinck, 1948 is considered to be a junior synonym of L. coomansi Laidlaw, 1936. The true male of L. pasia van Tol, 1990 is described for the first time; male specimens previously treated as L. pasia or L. cf pasia actually belong to a taxon closely allied to, and possibly merely a form of, L. coomansi. A description is given of the female of another new species, but the species is not named in the absence of the male. Female specimens from south-western Sarawak, similar to L. williamsoni Laidlaw, 1912, are considered likely to also represent a distinct species. The female of L. pendleburyi Laidlaw, 1934 is described for the first time and fresh descriptions of the males of L. coomansi, L. pendleburyi and L. williamsoni, and the female of L. coomansi are given. Keys to both sexes, and distribution maps are given. A molecular analysis of the Bornean species (except L. schieli) using the COI and ITS markers is presented.
    Matched MeSH terms: Borneo
  20. Fulltext Genetic Diversity and Clustering of the Rhoptry Associated Protein-1 of Plasmodium knowlesi from Peninsular Malaysia and Malaysian Borneo
    Azlan UW, Lau YL, Fong MY
    Korean J Parasitol, 2022 Dec;60(6):393-400.
    PMID: 36588415 DOI: 10.3347/kjp.2022.60.6.393
    Human infection with simian malaria Plasmodium knowlesi is a cause for concern in Southeast Asian countries, especially in Malaysia. A previous study on Peninsular Malaysia P. knowlesi rhoptry associated protein-1 (PkRAP1) gene has discovered the existence of dimorphism. In this study, genetic analysis of PkRAP1 in a larger number of P. knowlesi samples from Malaysian Borneo was conducted. The PkRAP1 of these P. knowlesi isolates was PCR-amplified and sequenced. The newly obtained PkRAP1 gene sequences (n = 34) were combined with those from the previous study (n = 26) and analysed for polymorphism and natural selection. Sequence analysis revealed a higher genetic diversity of PkRAP1 compared to the previous study. Exon II of the gene had higher diversity (π = 0.0172) than exon I (π = 0.0128). The diversity of the total coding region (π = 0.0167) was much higher than those of RAP1 orthologues such as PfRAP-1 (π = 0.0041) and PvRAP1 (π = 0.00088). Z-test results indicated that the gene was under purifying selection. Phylogenetic tree and haplotype network showed distinct clustering of Peninsular Malaysia and Malaysian Borneo PkRAP1 haplotypes. This geographical-based clustering of PkRAP1 haplotypes provides further evidence of the dimorphism of the gene and possible existence of 2 distinct P. knowlesi lineages in Malaysia.
    Matched MeSH terms: Borneo
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