Displaying publications 161 - 180 of 250 in total

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  1. Dickinson L, Noble H, Gardner E, Puad ASA, Zakaria WNFW, Zerega NJC
    PeerJ, 2020;8:e9897.
    PMID: 33005490 DOI: 10.7717/peerj.9897
    Limestone karsts of Southeast Asia can harbor high levels of endemism, but are highly fragmented, increasingly threatened, and their biodiversity is often poorly studied. This is true of the Padawan Limestone Area of Sarawak, Malaysia, home to the endemic Artocarpus annulatus, the closest known wild relative of two important and underutilized fruit tree crops, jackfruit (A. heterophyllus) and cempedak (A. integer). Identifying and conserving crop wild relatives is critical for the conservation of crop genetic diversity and breeding. In 2016 and 2017, five A. annulatus populations were located, and leaf material, locality information, and demographic data were collected. Microsatellite markers were used to assess genetic diversity and structure among populations, and to compare levels of genetic diversity to closely related congeneric species. Results indicate no evidence of inbreeding in A. annulatus, and there is no genetic structure among the five populations. However, diversity measures trended lower in seedlings compared to mature trees, suggesting allelic diversity may be under threat in the youngest generation of plants. Also, genetic diversity is lower in A. annulatus compared to closely related congeners. The present study provides a baseline estimate of A. annulatus genetic diversity that can be used for comparison in future studies and to other species in the unique limestone karst ecosystems. Considerations for in situ and ex situ conservation approaches are discussed.
    Matched MeSH terms: Microsatellite Repeats
  2. Neik TX, Chai JY, Tan SY, Sudo MPS, Cui Y, Jayaraj J, et al.
    G3 (Bethesda), 2019 09 04;9(9):2941-2950.
    PMID: 31292156 DOI: 10.1534/g3.119.400021
    Weedy crop relatives are among the world's most problematic agricultural weeds, and their ability to rapidly evolve can be enhanced by gene flow from both domesticated crop varieties and wild crop progenitor species. In this study, we examined the role of modern commercial crop cultivars, traditional landraces, and wild relatives in the recent emergence and proliferation of weedy rice in East Malaysia on the island of Borneo. This region of Malaysia is separated from the Asian continent by the South China Sea, and weedy rice has become a major problem there more recently than on the Malaysian peninsular mainland. Using 24 polymorphic SSR loci and genotype data from the awn-length domestication gene An-1, we assessed the genetic diversity, population structure and potential origins of East Malaysian weeds; 564 weedy, cultivated and wild rice accessions were analyzed from samples collected in East Malaysia, Peninsular Malaysia and neighboring countries. While there is considerable evidence for contributions of Peninsular Malaysian weed ecotypes to East Malaysian populations, we find that local crop cultivars and/or landraces from neighboring countries are also likely contributors to the weedy rice infestations. These findings highlight the implications of genetic admixture from different cultivar source populations in the spread of weedy crop relatives and the urgent need for preventive measurements to maintain sustainable crop yields.
    Matched MeSH terms: Microsatellite Repeats
  3. Cheah PL, Li J, Looi LM, Koh CC, Lau TP, Chang SW, et al.
    Malays J Pathol, 2019 Aug;41(2):91-100.
    PMID: 31427545
    Since 2014, the National Comprehensive Cancer Network (NCCN) has recommended that colorectal carcinoma (CRC) be universally tested for high microsatellite instability (MSI-H) which is present in 15% of such cancers. Fidelity of resultant microsatellites during DNA replication is contingent upon an intact mismatch repair (MMR) system and lack of fidelity can result in tumourigenesis. Prior to commencing routine screening for MSI-H, we assessed two commonly used methods, immunohistochemical (IHC) determination of loss of MMR gene products viz MLH1, MSH2, MSH6 and PMS2 against PCR amplification and subsequent fragment analysis of microsatellite markers, BAT25, BAT26, D2S123, D5S346 and D17S250 (Bethesda markers) in 73 unselected primary CRC. 15.1% (11/73) were categorized as MSI-H while deficient MMR (dMMR) was detected in 16.4% (12/73). Of the dMMR, 66.7% (8/12) were classified MSI-H, while 33.3% (4/12) were microsatellite stable/low microsatellite instability (MSS/MSI-L). Of the proficient MMR (pMMR), 95.1% (58/61) were MSS/MSI-L and 4.9% (3/61) were MSI-H. The κ value of 0.639 (standard error =0.125; p = 0.000) indicated substantial agreement between detection of loss of DNA mismatch repair using immunohistochemistry and the detection of downstream microsatellite instability using PCR. After consideration of advantages and shortcomings of both methods, it is our opinion that the choice of preferred technique for MSI analysis would depend on the type of laboratory carrying out the testing.
    Matched MeSH terms: Microsatellite Repeats
  4. Azman A, Ng KK, Ng CH, Lee CT, Tnah LH, Zakaria NF, et al.
    Sci Rep, 2020 11 05;10(1):19112.
    PMID: 33154411 DOI: 10.1038/s41598-020-76092-4
    Worldwide, many mangrove species are experiencing significant population declines, including Rhizophora apiculata, which is one of the most widespread and economically important species in tropical Asia. In Malaysia, there has been an alarming decline in R. apiculata populations driven primarily by anthropogenic activities. However, the lack of genetic and demographic information on this species has hampered local efforts to conserve it. To address these gaps, we generated novel genetic information for R. apiculata, based on 1,120 samples collected from 39 natural populations in Peninsular Malaysia. We investigated its genetic diversity and genetic structure with 19 transcriptome and three nuclear microsatellite markers. Our analyses revealed a low genetic diversity (mean He: 0.352) with significant genetic differentiation (FST: 0.315) among populations of R. apiculata. Approximately two-third of the populations showed significant excess of homozygotes, indicating persistent inbreeding which might be due to the decrease in population size or fragmentation. From the cluster analyses, the populations investigated were divided into two distinct clusters, comprising the west and east coasts of Peninsular Malaysia. The western cluster was further divided into two sub-clusters with one of the sub-clusters showing strong admixture pattern that harbours high levels of genetic diversity, thus deserving high priority for conservation.
    Matched MeSH terms: Microsatellite Repeats
  5. Chen Z, Ding G, Wang Y, Xu J, Lin Z
    J Genet, 2018 Nov 14;97(5):e147-e151.
    PMID: 30574879
    The tiger frog Hoplobatrachus rugulosus (Wiegmann 1834) is a large robust dicroglossid frog widely distributed in southern China, Malaysia, Myanmar, Vietnam and Thailand. The escaped bred tiger frog introduced from Thailand hybridized with Chinese native population may have affected the genetic diversity of local Chinese tiger frogs. However, previous microsatellite loci of this species do not offer enough information to construct the genetic map. Here, we reported 33 new microsatellite loci from transcriptome sequencing for H. rugulosus. Alleles ranged between 1 and 10 per locus and only one locus (HRT001) was monomorphic. The polymorphic information content, observed and expected heterozygosity were 0-0.794, 0-0.969 and 0-0.831, respectively. None of the loci was observed in linkage disequilibrium and two loci (HRT023 and HRT068) deviated from Hardy-Weinberg equilibrium after Bonferroni correction for multiple tests. These transcriptome-derived microsatellite markers will be usedto study the genetic divergence and construct the genetic map in H. rugulosus.
    Matched MeSH terms: Microsatellite Repeats
  6. Maryam Jamielah Yusoff, Zahirunisa Abd Rahim, Nurul Amiera Ghazi, Shi-Kee Chin, Mohd Jokha Yahya, Noor Lita Adam, et al.
    MyJurnal
    Introduction: Association studies between single nucleotide polymorphisms (SNPs) and type 2 diabetes mellitus (T2DM) have been abundant. However, there are limited reports on copy number variations (CNVs) of beta-defen- sins (DEFB) gene in relation to T2DM. In this study, DEFB copy numbers were quantified in T2DM with nephropathy, T2DM without nephropathy and non-diabetic control groups to investigate its influence in chronic inflammation in Malaysian individuals. Methods: DEFB copy number in Malaysian individuals were quantified by using paralogue ratio tests (PRT) which allow direct quantification of gene copy number by using PRT107A and HSPD21 PRT primers. The copy number generated was then validated from insertion/deletion ratio measurement 5DEL (rs5889219) and two microsatellite analyses (EPEV-1 and EPEV-3). Results: DEFB copy number was found extending from 2 to 8 cop- ies in the non-diabetic group (n=146), while in T2DM group (n=392), copy numbers were more extensive, ranging between 1 and 12 copies; with 1, 10 and 12 copies detected in T2DM with nephropathy group (n=202). Statistically, there is no significant difference in DEFB copy number between T2DM and the non-diabetic group (p=0.209) as well as between diabetic nephropathy and without nephropathy of the T2DM group (p=0.522). However, significant white blood cell (WBC) count was found between T2DM groups with and without diabetic nephropathy (p=0.000). Conclusion: Extreme DEFB copy numbers in T2DM with nephropathy group suggest future studies with bigger sam- ple size are necessary to elucidate the true impact of CNVs of DEFB gene in promoting early onset of nephropathy in T2DM.

    Matched MeSH terms: Microsatellite Repeats
  7. Hakim HM, Khan HO, Ismail SA, Lalung J, Kofi AE, Abdullah MT, et al.
    Data Brief, 2020 Aug;31:105909.
    PMID: 32642519 DOI: 10.1016/j.dib.2020.105909
    This data article provides population frequencies for 21 autosomal and two sex determining short tandem repeat (STR) loci in unrelated Kedayan individuals. This article is related to the research paper entitled "Forensic parameters and ancestral fraction in the Kedayan population inferred using 21 autosomal STR loci" [1] where these same data were subjected to ancestry and forensic analyses. We have collected 200 blood samples consisting of 128 male and 72 female volunteer representatives from Kedayan people residing in various parts of Borneo. All 23 STR loci were simultaneously amplified using Globalfiler™ Express PCR and amplicons were separated using an ABI 3500xl Genetic Analyzer. The STR allele calls at each locus were called using GeneMapperⓇ ID-X Software v1.4, while several algorithms in Arlequin software version 3.5 were used to estimate Hardy-Weinberg equilibrium (HWE) and linkage disequilibrium (LD) between pairs of STR loci.
    Matched MeSH terms: Microsatellite Repeats
  8. Muhammad NAF, Kassim NFA, Ab Majid AH, Wajidi MFF, Jamsari AFJ, Dieng H, et al.
    Trop Biomed, 2018 Dec 01;35(4):1049-1063.
    PMID: 33601852
    The medically important mosquito, Aedes albopictus is native to Asia and has become a major health concern in most Asian countries including Malaysia. Being recognized as a dengue vector, a clearer understanding of how mosquito populations are geographically connected, may therefore represent a profound yet significant understanding of control strategies. There are no documented reports on the genetic structure of Ae. albopictus populations from different developed settlements inferred from microsatellite DNA markers in Malaysia, particularly in Penang Island (Northern Peninsular Malaysia). Here, we assessed the molecular population genetics of Ae. albopictus in terms of their allelic variation, genetic diversity and population structure. A total of 42 mosquitoes were sampled from Jelutong, Batu Maung and Balik Pulau which represented urban, suburban and rural areas in Penang Island respectively and analysed for polymorphism at six microsatellite loci. All of the microsatellite markers were successfully amplified and were polymorphic, showing low genetic structure among geographic populations (FST= 0.0362). It is supported with admixture individuals observed in STRUCTURE and FCA and this suggests that high gene flow has been experienced between populations. These findings implicate passive dispersal through human-aided transportation; as a factor shaping the genetic structure of Ae. albopictus populations in Penang Island.
    Matched MeSH terms: Microsatellite Repeats
  9. Daud, S.S., Ibrahim, K., Ariffin, H.
    JUMMEC, 2007;10(1):11-16.
    MyJurnal
    We aimed to establish a method for quantitative analysis of mixed haematopoietic chimerism based on microchip electrophoresis of selected molecular markers following PCR amplification for accurate monitoring of graft status post-transplantation. A 12-year-old girl with relapsed acute lymphoblastic leukaemia who underwent allogeneic bone marrow transplantation had qualitative chimerism analysis using short tandem repeat markers at three time points following the procedure. Her archived DNA samples were then used to test the ability to correlate her clinical course with changes in the quantity of donor chimerism at the different time points. Quantitative chimerism analysis was performed on the Agilent 2100 bioanalyser and donor-recipient ratios were calculated from generated electropherograms. Complete donor chimerism (98%) was demonstrated three weeks post- transplantation. Decreasing amount of donor chimerism to 24% was shown after three months and this concurred with clinical relapse. Following a second transplant, full donor chimerism was reestablished where donor chimerism rose to 100%. High resolution microchip electrophoresis could be useful in predicting the occurrence of increasing recipient chimerism which may herald impending relapse in patients while the disease burden is still low. This investigational approach may provide useful information for clinicians to select appropriate intervention strategies to ensure successful transplantation.
    Matched MeSH terms: Microsatellite Repeats
  10. Rodrigues, K. F., Yeoh, K. A., Kumar, S. V.
    MyJurnal
    Geographically isolated populations of endemic orchids have evolved and adapted to an existence within specifi c ecological niches. These populations are highly susceptible to anthropogenic
    infl uences on their microhabitats. The primary objective of conservation programs is the restoration of endangered populations to their ecologically sustainable levels, and the fi rst stage in the process of conservation involves estimation of molecular diversity at the level of the population. The approach described in this article involves the application of RAPD, Microsatellites and Chloroplast DNA markers for the characterization of the genetic structure of Paphiopedilum rothschildianum and Phalaenopsis gigantea, two endangered and endemic orchids of Sabah. This study has isolated a total of 96 microsatellite loci in P. rothschildianum and P. gigantea, 42 specifi c primer pairs have been designed for amplifi cation of microsatellite loci and are currently being applied to screen the breeding pools. The Chloroplast DNA regions amplifi ed by the primer pairs trnH-psbA and trnL-trnF exhibit distinct polymorphisms and can be used to establish phylogenetic
    relationships. The ability of microsatellite loci to cross-amplify selected varieties of orchids has been determined. The molecular markers developed will be applied to estimate population diversity
    levels and to formulate long-term management strategies for the conservation of endangered species of orchids of Sabah.
    Matched MeSH terms: Microsatellite Repeats
  11. Tan, Soon Guan
    MyJurnal
    In various biological studies, for example those in population genetics, conservation biology, forensic science, gene mapping, breed, strain and population characterization and identification, marker assisted selection and the identification of cryptic species complexes, codominant genetic markers play important roles. The information that can be gained from them are far superior than those from dominant markers like random amplified polymorphic DNA (RAPD), amplified fragment length polymorphisms (AFLP), direct amplification of length polymorphisms (DALP) and randomly amplified microsatellites (RAM) or inter simple sequence repeats (ISSR).
    Matched MeSH terms: Microsatellite Repeats
  12. Menchaca A, Rossi NA, Froidevaux J, Dias-Freedman I, Caragiulo A, Wultsch C, et al.
    BMC Genet, 2019 12 27;20(1):100.
    PMID: 31881935 DOI: 10.1186/s12863-019-0801-5
    BACKGROUND: Connectivity among jaguar (Panthera onca) populations will ensure natural gene flow and the long-term survival of the species throughout its range. Jaguar conservation efforts have focused primarily on connecting suitable habitat in a broad-scale. Accelerated habitat reduction, human-wildlife conflict, limited funding, and the complexity of jaguar behaviour have proven challenging to maintain connectivity between populations effectively. Here, we used non-invasive genetic sampling and individual-based conservation genetic analyses to assess genetic diversity and levels of genetic connectivity between individuals in the Cockscomb Basin Wildlife Sanctuary and the Maya Forest Corridor. We used expert knowledge and scientific literature to develop models of landscape permeability based on circuit theory with fine-scale landscape features as ecosystem types, distance to human settlements and roads to predict the most probable jaguar movement across central Belize.

    RESULTS: We used 12 highly polymorphic microsatellite loci to identify 50 individual jaguars. We detected high levels of genetic diversity across loci (HE = 0.61, HO = 0.55, and NA = 9.33). Using Bayesian clustering and multivariate models to assess gene flow and genetic structure, we identified one single group of jaguars (K = 1). We identified critical areas for jaguar movement that fall outside the boundaries of current protected areas in central Belize. We detected two main areas of high landscape permeability in a stretch of approximately 18 km between Sittee River Forest Reserve and Manatee Forest Reserve that may increase functional connectivity and facilitate jaguar dispersal from and to Cockscomb Basin Wildlife Sanctuary. Our analysis provides important insights on fine-scale genetic and landscape connectivity of jaguars in central Belize, an area of conservation concern.

    CONCLUSIONS: The results of our study demonstrate high levels of relatively recent gene flow for jaguars between two study sites in central Belize. Our landscape analysis detected corridors of expected jaguar movement between the Cockscomb Basin Wildlife Sanctuary and the Maya Forest Corridor. We highlight the importance of maintaining already established corridors and consolidating new areas that further promote jaguar movement across suitable habitat beyond the boundaries of currently protected areas. Continued conservation efforts within identified corridors will further maintain and increase genetic connectivity in central Belize.

    Matched MeSH terms: Microsatellite Repeats
  13. Chang W, Ee-Uli J, Ng WL, Rovie-Ryan JJ, Tan SG, Yong CSY
    Sci Rep, 2019 06 11;9(1):8504.
    PMID: 31186469 DOI: 10.1038/s41598-019-44870-4
    Macaca fascicularis, also known as the cynomolgus macaque, is an important non-human primate animal model used in biomedical research. It is an Old-World primate widely distributed in Southeast Asia and is one of the most abundant macaque species in Malaysia. However, the genetic structure of wild cynomolgus macaque populations in Malaysia has not been thoroughly elucidated. In this study, we developed genic-simple sequence repeat (genic-SSR) markers from an in-house transcriptome dataset generated from the Malaysian cynomolgus macaque via RNA sequencing, and applied these markers on 26 cynomolgus macaque individuals. A collection of 14,751 genic-SSRs were identified, where 13,709 were perfect SSRs. Dinucleotide repeats were the most common repeat motifs with a frequency of 65.05%, followed by trinucleotide repeats (20.55%). Subsequently, we designed 300 pairs of primers based on perfect di- and trinucleotide SSRs, in which 105 SSRs were associated with functional genes. A subset of 30 SSR markers were randomly selected and validated, yielding 19 polymorphic markers with an average polymorphism information content value of 0.431. The development of genic-SSR markers in this study is indeed timely to provide useful markers for functional and population genetic studies of the cynomolgus macaque and other related non-human primate species.
    Matched MeSH terms: Microsatellite Repeats
  14. Najihah A, Nur Ain Izzati M, Yong S, Nik Mohd Izham M
    Sains Malaysiana, 2017;46:2425-2432.
    Fusarium species are known to cause various diseases on plantations including fruits and vegetables. The most common Fusarium that can cause plant diseases are Fusarium proliferatum and Fusarium verticillioides. Ear rot disease on maize, wilt disease on cucurbits and fruit rot disease on tomato as well as banana are example of diseases caused by these two species. The objectives of this study were to identify F. proliferatum and F. verticillioides based on species-specific primers and polymerase chain reaction (PCR) amplification and to evaluate the genetic diversity of both species based on microsatellite markers. Fifty isolates of Fusarium species that were previously collected throughout Malaysia from different hosts were identified by using species-specific PCR amplification. Twenty-nine isolates were identified as F. proliferatum and 21 isolates were identified as F. verticillioides based on species-specific primer. The genetic diversity of all the fungal isolates was evaluated by using microsatellite analysis with six established primers. Five out of six primers amplified polymorphic bands with the most effective primer showing high polymorphism were (AG)7C and (TCC)5 meanwhile one primer (TTTC)4 gave negative result with no band amplified. The phylogenetic tree that was constructed showing two different clades distinguished between F. proliferatum and F. verticillioides.
    Matched MeSH terms: Microsatellite Repeats
  15. Kofi AE, Hakim HM, Khan HO, Ismail SA, Ghansah A, Haslindawaty ARN, et al.
    Data Brief, 2020 Aug;31:105746.
    PMID: 32490095 DOI: 10.1016/j.dib.2020.105746
    Short tandem repeat (STR) loci are widely used as genetic marker for ancestral and forensic analyses. The latter application includes for paternity testing and DNA profiling of samples collected from scenes of crime and suspects. This survey provides the first dataset for 21 STR loci across the Akan population in Ghana by genotyping of 109 unrelated healthy individuals using Investigator 24plex kit. None of the STR loci screened deviated from Hardy-Weinberg equilibrium after applying Bonferroni correction. Overall, 224 unique alleles were observed with allele frequencies ranging from 0.005 to 0.518. The combined match probability, combined power of exclusion and combined power discrimination were 1 in 4.07 × 10-25, 0.999999999 and 1, respectively. Principal coordinate analysis carried out using 21 STR allele frequency data mapped the Akans with Nigerian subpopulation groups (Hausa, Igbo and Yoruba), but separated from Thais of Thailand, Chechen of Jordan and Tijuana of Mexico.
    Matched MeSH terms: Microsatellite Repeats
  16. Gan ST, Wong WC, Wong CK, Soh AC, Kilian A, Low EL, et al.
    J Appl Genet, 2018 Feb;59(1):23-34.
    PMID: 29214520 DOI: 10.1007/s13353-017-0420-7
    Oil palm (Elaeis guineensis Jacq.) is an outbreeding perennial tree crop with long breeding cycles, typically 12 years. Molecular marker technologies can greatly improve the breeding efficiency of oil palm. This study reports the first use of the DArTseq platform to genotype two closely related self-pollinated oil palm populations, namely AA0768 and AA0769 with 48 and 58 progeny respectively. Genetic maps were constructed using the DArT and SNP markers generated in combination with anchor SSR markers. Both maps consisted of 16 major independent linkage groups (2n = 2× = 32) with 1399 and 1466 mapped markers for the AA0768 and AA0769 populations, respectively, including the morphological trait "shell-thickness" (Sh). The map lengths were 1873.7 and 1720.6 cM with an average marker density of 1.34 and 1.17 cM, respectively. The integrated map was 1803.1 cM long with 2066 mapped markers and average marker density of 0.87 cM. A total of 82% of the DArTseq marker sequence tags identified a single site in the published genome sequence, suggesting preferential targeting of gene-rich regions by DArTseq markers. Map integration of higher density focused around the Sh region identified closely linked markers to the Sh, with D.15322 marker 0.24 cM away from the morphological trait and 5071 bp from the transcriptional start of the published SHELL gene. Identification of the Sh marker demonstrates the robustness of using the DArTseq platform to generate high density genetic maps of oil palm with good genome coverage. Both genetic maps and integrated maps will be useful for quantitative trait loci analysis of important yield traits as well as potentially assisting the anchoring of genetic maps to genomic sequences.
    Matched MeSH terms: Microsatellite Repeats
  17. Purayil FT, Robert GA, Gothandam KM, Kurup SS, Subramaniam S, Cheruth AJ
    3 Biotech, 2018 Feb;8(2):109.
    PMID: 29430370 DOI: 10.1007/s13205-018-1108-3
    Nine (9) different date palm (Phoenix dactylifera L.) cultivars from UAE, which differ in their flower timings were selected to determine the polymorphism and genetic relationship between these cultivars. Hereditary differences and interrelationships were assessed utilizing inter-simple sequence repeat (ISSR) and directed amplification of minisatellite DNA region (DAMD) primers. Analysis on eight DAMD and five ISSR markers produced total of 113 amplicon including 99 polymorphic and 14 monomorphic alleles with a polymorphic percentage of 85.45. The average polymorphic information content for the two-marker system was almost similar (DAMD, 0.445 and ISSR, 0.459). UPGMA based clustering of DAMD and ISSR revealed that mid-season cultivars, Mkh (Khlas) and MB (Barhee) grouped together to form a subcluster in both the marker systems. The genetic similarity analysis followed by clustering of the cumulative data from the DAMD and ISSR resulted in two major clusters with two early-season cultivars (ENg and Ekn), two mid-season cultivars (MKh and MB) and one late-season cultivar (Lkhs) in cluster 1, cluster 2 includes two late-season cultivars, one early-season cultivar and one mid-season cultivar. The cluster analysis of both DAMD and ISSR marker revealed that, the patterns of variation between some of the tested cultivars were similar in both DNA marker systems. Hence, the present study signifies the applicability of DAMD and ISSR marker system in detecting genetic diversity of date palm cultivars flowering at different seasons. This may facilitate the conservation and improvement of date palm cultivars in the future.
    Matched MeSH terms: Microsatellite Repeats
  18. Siew GY, Ng WL, Tan SW, Alitheen NB, Tan SG, Yeap SK
    PeerJ, 2018;6:e4266.
    PMID: 29511604 DOI: 10.7717/peerj.4266
    Durian (Durio zibethinus) is one of the most popular tropical fruits in Asia. To date, 126 durian types have been registered with the Department of Agriculture in Malaysia based on phenotypic characteristics. Classification based on morphology is convenient, easy, and fast but it suffers from phenotypic plasticity as a direct result of environmental factors and age. To overcome the limitation of morphological classification, there is a need to carry out genetic characterization of the various durian types. Such data is important for the evaluation and management of durian genetic resources in producing countries. In this study, simple sequence repeat (SSR) markers were used to study the genetic variation in 27 durian types from the germplasm collection of Universiti Putra Malaysia. Based on DNA sequences deposited in Genbank, seven pairs of primers were successfully designed to amplify SSR regions in the durian DNA samples. High levels of variation among the 27 durian types were observed (expected heterozygosity,H
    E
     = 0.35). The DNA fingerprinting power of SSR markers revealed by the combined probability of identity (PI) of all loci was 2.3×10-3. Unique DNA fingerprints were generated for 21 out of 27 durian types using five polymorphic SSR markers (the other two SSR markers were monomorphic). We further tested the utility of these markers by evaluating the clonal status of shared durian types from different germplasm collection sites, and found that some were not clones. The findings in this preliminary study not only shows the feasibility of using SSR markers for DNA fingerprinting of durian types, but also challenges the current classification of durian types, e.g., on whether the different types should be called "clones", "varieties", or "cultivars". Such matters have a direct impact on the regulation and management of durian genetic resources in the region.
    Matched MeSH terms: Microsatellite Repeats
  19. Ismail NA, Rafii MY, Mahmud TM, Hanafi MM, Miah G
    Mol Biol Rep, 2016 Dec;43(12):1347-1358.
    PMID: 27585572
    Ginger is an economically important and valuable plant around the world. Ginger is used as a food, spice, condiment, medicine and ornament. There is available information on biochemical aspects of ginger, but few studies have been reported on its molecular aspects. The main objective of this review is to accumulate the available molecular marker information and its application in diverse ginger studies. This review article was prepared by combing material from published articles and our own research. Molecular markers allow the identification and characterization of plant genotypes through direct access to hereditary material. In crop species, molecular markers are applied in different aspects and are useful in breeding programs. In ginger, molecular markers are commonly used to identify genetic variation and classify the relatedness among varieties, accessions, and species. Consequently, it provides important input in determining resourceful management strategies for ginger improvement programs. Alternatively, a molecular marker could function as a harmonizing tool for documenting species. This review highlights the application of molecular markers (isozyme, RAPD, AFLP, SSR, ISSR and others such as RFLP, SCAR, NBS and SNP) in genetic diversity studies of ginger species. Some insights on the advantages of the markers are discussed. The detection of genetic variation among promising cultivars of ginger has significance for ginger improvement programs. This update of recent literature will help researchers and students select the appropriate molecular markers for ginger-related research.
    Matched MeSH terms: Microsatellite Repeats
  20. Divis PCS, Hu TH, Kadir KA, Mohammad DSA, Hii KC, Daneshvar C, et al.
    Emerg Infect Dis, 2020 07;26(7):1392-1398.
    PMID: 32568035 DOI: 10.3201/eid2607.190924
    Population genetic analysis revealed that Plasmodium knowlesi infections in Malaysian Borneo are caused by 2 divergent parasites associated with long-tailed (cluster 1) and pig-tailed (cluster 2) macaques. Because the transmission ecology is likely to differ for each macaque species, we developed a simple genotyping PCR to efficiently distinguish between and survey the 2 parasite subpopulations. This assay confirmed differences in the relative proportions in areas of Kapit division of Sarawak state, consistent with multilocus microsatellite analyses. Analyses of 1,204 human infections at Kapit Hospital showed that cluster 1 caused approximately two thirds of cases with no significant temporal changes from 2000 to 2018. We observed an apparent increase in overall numbers in the most recent 2 years studied, driven mainly by increased cluster 1 parasite infections. Continued monitoring of the frequency of different parasite subpopulations and correlation with environmental alterations are necessary to determine whether the epidemiology will change substantially.
    Matched MeSH terms: Microsatellite Repeats
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