Displaying publications 41 - 60 of 730 in total

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  1. Oladosu Y, Rafii MY, Abdullah N, Abdul Malek M, Rahim HA, Hussin G, et al.
    ScientificWorldJournal, 2014;2014:190531.
    PMID: 25431777 DOI: 10.1155/2014/190531
    Genetic based knowledge of different vegetative and yield traits play a major role in varietal improvement of rice. Genetic variation gives room for recombinants which are essential for the development of a new variety in any crop. Based on this background, this work was carried out to evaluate genetic diversity of derived mutant lines and establish relationships between their yield and yield components using multivariate analysis. To achieve this objective, two field trials were carried out on 45 mutant rice genotypes to evaluate their growth and yield traits. Data were taken on vegetative traits and yield and its components, while genotypic and phenotypic coefficients, variance components, expected genetic advance, and heritability were calculated. All the genotypes showed variations for vegetative traits and yield and its components. Also, there was positive relationship between the quantitative traits and the final yield with the exception of number of tillers. Finally, the evaluated genotypes were grouped into five major clusters based on the assessed traits with the aid of UPGMA dendrogram. So hybridization of group I with group V or group VI could be used to attain higher heterosis or vigour among the genotypes. Also, this evaluation could be useful in developing reliable selection indices for important agronomic traits in rice.
    Matched MeSH terms: Genetic Variation/genetics*
  2. Taheri S, Abdullah TL, Abdullah NA, Ahmad Z, Karimi E, Shabanimofrad MR
    Genet. Mol. Res., 2014;13(3):7339-46.
    PMID: 25222232 DOI: 10.4238/2014.September.5.12
    The genus Curcuma is a member of the ginger family (Zingiberaceae) that has recently become popular for use as flowering pot plants, both indoors and as patio and landscape plants. We used PCR-based molecular markers (SSRs) to elucidate genetic variation and relationships between five varieties of Curcuma (Curcuma alismatifolia) cultivated in Malaysia. Of the primers tested, 8 (of 17) SSR primers were selected for their reproducibility and high rates of polymorphism. The number of presumed alleles revealed by the SSR analysis ranged from two to six alleles, with a mean value of 3.25 alleles per locus. The values of HO and HE ranged from 0 to 0.8 (mean value of 0.2) and 0.1837 to 0.7755 (mean value of 0.5102), respectively. Eight SSR primers yielded 26 total amplified fragments and revealed high rates of polymorphism among the varieties studied. The polymorphic information content varied from 0.26 to 0.73. Dice's similarity coefficient was calculated for all pairwise comparisons and used to construct an unweighted pair group method with arithmetic average (UPGMA) dendrogram. Similarity coefficient values from 0.2105 to 0.6667 (with an average of 0.4386) were found among the five varieties examined. A cluster analysis of data using a UPGMA algorithm divided the five varieties/hybrids into 2 groups.
    Matched MeSH terms: Genetic Variation*
  3. Ramaiya SD, Bujang JS, Zakaria MH
    ScientificWorldJournal, 2014;2014:598313.
    PMID: 25050402 DOI: 10.1155/2014/598313
    This study used morphological characterization and phylogenetic analysis of the internal transcribed spacer (ITS) region of nuclear ribosomal DNA to investigate the phylogeny of Passiflora species. The samples were collected from various regions of East Malaysia, and discriminant function analysis based on linear combinations of morphological variables was used to classify the Passiflora species. The biplots generated five distinct groups discriminated by morphological variables. The group consisted of cultivars of P. edulis with high levels of genetic similarity; in contrast, P. foetida was highly divergent from other species in the morphological biplots. The final dataset of aligned sequences from nine studied Passiflora accessions and 30 other individuals obtained from GenBank database (NCBI) yielded one most parsimonious tree with two strongly supported clades. Maximum parsimony (MP) tree showed the phylogenetic relationships within this subgenus Passiflora support the classification at the series level. The constructed phylogenic tree also confirmed the divergence of P. foetida from all other species and the closeness of wild and cultivated species. The phylogenetic relationships were consistent with results of morphological assessments. The results of this study indicate that ITS region analysis represents a useful tool for evaluating genetic diversity in Passiflora at the species level.
    Matched MeSH terms: Genetic Variation*
  4. Asnet MJ, Rubia AG, Ramya G, Nagalakshmi RN, Shenbagarathai R
    J Vector Borne Dis, 2014 Jun;51(2):82-5.
    PMID: 24947213
    DENVirDB is a web portal that provides the sequence information and computationally curated information of dengue viral proteins. The advent of genomic technology has increased the sequences available in the public databases. In order to create relevant concise information on Dengue Virus (DENV), the genomic sequences were collected, analysed with the bioinformatics tools and presented as DENVirDB. It provides the comprehensive information of complete genome sequences of dengue virus isolates of Southeast Asia, viz. India, Bangladesh, Sri Lanka, East Timor, Philippines, Malaysia, Papua New Guinea, Brunei and China. DENVirDB also includes the structural and non-structural protein sequences of DENV. It intends to provide the integrated information on the physicochemical properties, topology, secondary structure, domain and structural properties for each protein sequences. It contains over 99 entries in complete genome sequences and 990 entries in protein sequences, respectively. Therefore, DENVirDB could serve as a user friendly database for researchers in acquiring sequences and proteomic information in one platform.
    Matched MeSH terms: Genetic Variation*
  5. Abu-Bakar SB, Razali NM, Naggs F, Wade C, Mohd-Nor SA, Aileen-Tan SH
    Mol Biol Rep, 2014 Mar;41(3):1799-805.
    PMID: 24443224 DOI: 10.1007/s11033-014-3029-5
    A total of 30 specimens belonging to five species, namely; Cryptozona siamensis, Sarika resplendens and Sarika sp. from the family Ariophantidae as well as Quantula striata and Quantula sp. from the family Dyakiidae were collected from the Langkawi Island in Northern Peninsular Malaysia. All specimens were identified through comparisons of shell morphology and amplification of a 500 bp segment of the 16S rRNA mtDNA gene. To assess phylogenetic insights, the sequences were aligned using ClustalW and phylogenetic trees were constructed. The analyses showed two major lineages in both Maximum Parsimony and Neighbour Joining phylogenetic trees. Each putative taxonomic group formed a monophyletic cluster. Our study revealed low species and intraspecies genetic diversities based on the 16S rRNA gene sequences. Thus, this study has provided an insight of land snail diversity in populations of an island highly influenced by anthropogenic activities through complementary use of shell morphological and molecular data.
    Matched MeSH terms: Genetic Variation*
  6. Esa Y, Abdul Rahim KA
    Biomed Res Int, 2013;2013:170980.
    PMID: 24455674 DOI: 10.1155/2013/170980
    This study examines the population genetic structure of Tor tambroides, an important freshwater fish species in Malaysia, using fifteen polymorphic microsatellite loci and sequencing of 464 base pairs of the mitochondrial cytochrome c oxidase I (COI) gene. A total of 152 mahseer samples were collected from eight populations throughout the Malaysia river system. Microsatellites results found high levels of intrapopulation variations, but mitochondrial COI results found high levels of interpopulations differentiation. The possible reasons for their discrepancies might be the varying influence of genetic drift on each marker or the small sample sizes used in most of the populations. The Kelantan population showed very low levels of genetic variations using both mitochondrial and microsatellite analyses. Phylogenetic analysis of the COI gene found a unique haplotype (ER8∗), possibly representing a cryptic lineage of T. douronensis, from the Endau-Rompin population. Nevertheless, the inclusion of nuclear microsatellite analyses could not fully resolve the genetic identity of haplotype ER8∗ in the present study. Overall, the findings showed a serious need for more comprehensive and larger scale samplings, especially in remote river systems, in combination with molecular analyses using multiple markers, in order to discover more cryptic lineages or undescribed "genetic species" of mahseer.
    Matched MeSH terms: Genetic Variation*
  7. Rafii MY, Shabanimofrad M, Puteri Edaroyati MW, Latif MA
    Mol Biol Rep, 2012 Jun;39(6):6505-11.
    PMID: 22307785 DOI: 10.1007/s11033-012-1478-2
    A sum of 48 accessions of physic nut, Jatropha curcas L. were analyzed to determine the genetic diversity and association between geographical origin using RAPD-PCR markers. Eight primers generated a total of 92 fragments with an average of 11.5 amplicons per primer. Polymorphism percentages of J. curcas accessions for Selangor, Kelantan, and Terengganu states were 80.4, 50.0, and 58.7%, respectively, with an average of 63.04%. Jaccard's genetic similarity co-efficient indicated the high level of genetic variation among the accessions which ranged between 0.06 and 0.81. According to UPGMA dendrogram, 48 J. curcas accessions were grouped into four major clusters at coefficient level 0.3 and accessions from same and near states or regions were found to be grouped together according to their geographical origin. Coefficient of genetic differentiation (G(st)) value of J. curcas revealed that it is an outcrossing species.
    Matched MeSH terms: Genetic Variation*
  8. Taheri S, Abdullah TL, Abdullah NA, Ahmad Z
    Genet. Mol. Res., 2012;11(3):3069-76.
    PMID: 23007984
    The genus Curcuma is a member of the ginger family (Zingiberaceae) that has recently become popular for use as flowering pot plants, both indoors and as patio and landscape plants. We used PCR-based molecular markers (ISSRs) to assess genetic variation and relationships between five varieties of curcuma (Curcuma alismatifolia) cultivated in Malaysia. Sixteen ISSR primers generated 139 amplified fragments, of which 77% had high polymorphism among these varieties. These markers were used to estimate genetic similarity among the varieties using Jaccard's similarity coefficient. The similarity matrix was used to construct a dendrogram, and a principal component plot was developed to examine genetic relationships among varieties. Similarity coefficient values ranged from 0.40 to 0.58 (with a mean of 0.5) among the five varieties. The mean value of number of observed alleles, number of effective alleles, mean Nei's gene diversity, and Shannon's information index were 8.69, 1.48, 0.29, and 0.43, respectively.
    Matched MeSH terms: Genetic Variation*
  9. Darlina MN, Masazurah AR, Jayasankar P, Jamsari AF, Siti AM
    Genet. Mol. Res., 2011;10(3):2078-92.
    PMID: 21968625 DOI: 10.4238/vol10-3gmr1249
    Mackerel (Scombridae; Rastrelliger) are small commercially important pelagic fish found in tropical regions. They serve as a cheap source of animal protein and are commonly used as live bait. By using a truss morphometrics protocol and RAPD analysis, we examined morphological and genetic variation among 77 individual mackerel that were caught using long lines and gillnets at 11 locations along the west coast of Peninsular Malaysia. Nineteen morphometric traits were evaluated and genetic information was estimated using five 10-base RAPD random primers. Total DNA was extracted from muscle tissue. Morphometric discriminant function analysis revealed that two morphologically distinct groups of Rastrelliger kanagurta and a single group of R. brachysoma can be found along the west coast of Peninsular Malaysia. We also found that the head-related characters and those from the anterior part of the body of Rastrelliger spp significantly contribute to stock assessment of this population. RAPD analysis showed a trend similar to that of the morphometric analysis, suggesting a genetic component to the observed phenotypic differentiation. These data will be useful for developing conservation strategies for these species.
    Matched MeSH terms: Genetic Variation*
  10. Joy N, Prasanth VP, Soniya EV
    Genetica, 2011 Aug;139(8):1033-43.
    PMID: 21874534 DOI: 10.1007/s10709-011-9605-x
    The genotypes of black pepper are morphologically and genotypically highly diverse and carry all the cumulative variations inherited and maintained through generations. The present study describes the Simple Sequence Repeat (SSR) or microsatellite based assessment of genetic diversity among forty popular genotypes and four different species of black pepper in Southern region of India. For isolation of SSR primers, our earlier attempts with enrichment strategies like 'Triplex affinity capture' did not extract a single SSR primer due to close proximity of restriction sites to the SSR motif. Hence we developed a 'Sequential Reverse Genome Walking (SRGW)' strategy with better enrichment efficiency of 72% that generated seven new SSR primers. Genotyping precisely discriminated majority of genotypes which indicated that the SSR primers are very informative. A total of 62 alleles with an average of 15.5 alleles over 4 loci were identified. All the SSR primers showed an average Polymorphism Information Content (PIC) value of 0.85. The estimated average Shared Allele Frequency ranged between 1.57 and 20.12%. The PCA plot revealed four closely related individual groups and identified Karimunda, Wild pepper and a local landrace 'local b' as the most divergent genotypes. Cluster analysis exposed the genetic relatedness between hybrids and selections with other known cultivars. The introduction of black pepper from South India to Malaysia was emphasized from the observation of genetic similarity of Malaysian cultivar 'Kuching' with other indigenous popular cultivars. The study was first to portray the precise genetic relatedness among the major indigenous genotypes of black pepper.
    Matched MeSH terms: Genetic Variation/genetics*
  11. Wang L, Meng Z, Liu X, Zhang Y, Lin H
    Int J Mol Sci, 2011;12(7):4378-94.
    PMID: 21845084 DOI: 10.3390/ijms12074378
    In the present study, we employed microsatellite DNA markers to analyze the genetic diversity and differentiation between and within cultured stocks and wild populations of the orange-spotted grouper originating from the South China Sea and Southeast Asia. Compared to wild populations, genetic changes including reduced genetic diversity and significant differentiation have taken place in cultured grouper stocks, as shown by allele richness and heterozygosity studies, pairwise F(st), structure, molecular variance analysis, as well as multidimensional scaling analysis. Although two geographically adjacent orange-spotted grouper populations in China showed negligible genetic divergence, significant population differentiation was observed in wild grouper populations distributed in a wide geographical area from China, through Malaysia to Indonesia. However, the Mantel test rejected the isolation-by-distance model of genetic structure, which indicated the genetic differentiation among the populations could result from the co-effects of various factors, such as historical dispersal, local environment, ocean currents, river flows and island blocks. Our results demonstrated that microsatellite markers could be suitable not only for genetic monitoring cultured stocks but also for revealing the population structuring of wild orange-spotted grouper populations. Meanwhile, our study provided important information for breeding programs, management of cultured stocks and conservation of wild populations of the orange-spotted grouper.
    Matched MeSH terms: Genetic Variation*
  12. AlAama J, Smith TD, Lo A, Howard H, Kline AA, Lange M, et al.
    Hum Mutat, 2011 May;32(5):501-6.
    PMID: 21305654 DOI: 10.1002/humu.21463
    Genetic diseases are a pressing global health problem that requires comprehensive access to basic clinical and genetic data to counter. The creation of regional and international databases that can be easily accessed by clinicians and diagnostic labs will greatly improve our ability to accurately diagnose and treat patients with genetic disorders. The Human Variome Project is currently working in conjunction with human genetics societies to achieve this by establishing systems to collect every mutation reported by a diagnostic laboratory, clinic, or research laboratory in a country and store these within a national repository, or HVP Country Node. Nodes have already been initiated in Australia, Belgium, China, Egypt, Malaysia, and Kuwait. Each is examining how to systematically collect and share genetic, clinical, and biochemical information in a country-specific manner that is sensitive to local ethical and cultural issues. This article gathers cases of genetic data collection within countries and takes recommendations from the global community to develop a procedure for countries wishing to establish their own collection system as part of the Human Variome Project. We hope this may lead to standard practices to facilitate global collection of data and allow efficient use in clinical practice, research and therapy.
    Matched MeSH terms: Genetic Variation*
  13. Islam MM, Khan MM, Tjong DH, Alam MS, Sumida M
    Zoolog Sci, 2008 Mar;25(3):261-72.
    PMID: 18393563 DOI: 10.2108/zsj.25.261
    The present study was conducted to elucidate the genetic divergence and the phylogenetic relationships in the F. limnocharis complex from Bangladesh and other Asian countries such as Sri Lanka, Thailand, Malaysia, Taiwan and Japan by allozyme analyses. We used a total of 95 frogs of the F. limnocharis complex from these countries and F. cancrivora from the Philippines as an outgroup. Based on body size, the F. limnocharis complex from Bangladesh was divided into three distinct groups: large, medium and small types. Allozyme analyses were carried out with 28 loci encoding 20 enzymes and two blood proteins by horizontal starch-gel electrophoresis. When genetic distance was calculated, distinct divergence was found among the three types: mean genetic distance was 0.782 between the small and medium types, 1.458 between the large and medium types, and 1.520 between the large and small types. Phylogenetic trees based on genetic distance showed that all populations of Bangladesh small type strongly formed a cluster and were found to be most closely related to the Sri Lanka population; that all populations of Bangladesh large type formed a very strong cluster and were grouped with several populations from Thailand, Malaysia, Japan, and Taiwan; and that the medium type was segregated from all other groups. This may imply that each of the three types is a different species, and that the medium type is possibly an undescribed taxon.
    Matched MeSH terms: Genetic Variation*
  14. van Holst Pellekaan SM, Ingman M, Roberts-Thomson J, Harding RM
    Am. J. Phys. Anthropol., 2006 Oct;131(2):282-94.
    PMID: 16596590
    We classified diversity in eight new complete mitochondrial genome sequences and 41 partial sequences from living Aboriginal Australians into five haplogroups. Haplogroup AuB belongs to global lineage M, and AuA, AuC, AuD, and AuE to N. Within N, we recognize subdivisions, assigning AuA to haplogroup S, AuD to haplogroup O, AuC to P4, and AuE to P8. On available evidence, (S)AuA and (M)AuB are widespread in Australia. (P4)AuC is found in the Riverine region of western New South Wales, and was identified by others in northern Australia. (O)AuD and (P8)AuE were clearly identified only from central Australia. Our eight Australian full mt genome sequences, combined with 20 others (Ingman and Gyllensten 2003 Genome Res. 13:1600-1606) and compared with full mt genome sequences from regions to the north that include Papua New Guinea, Malaya, and Andaman and Nicobar Islands, show that ancestral connections between regions are deep and limited to clustering at the level of the N and M macrohaplogroups. The Australian-specific distribution of the five haplogroups identified indicates genetic isolation over a long period. Ancestral connections within Australia are deeper than those reflected by known linguistic or culturally based affinities. Applying a coalescence analysis to a gene tree for the coding regions of the eight genomic sequences, we made estimates of time depth that support a continuity of presence for the descendants of a founding population already established by 40,000 years ago.
    Matched MeSH terms: Genetic Variation*
  15. Wright TF, Johns PM, Walters JR, Lerner AP, Swallow JG, Wilkinson GS
    Genet. Res., 2004 Aug;84(1):27-40.
    PMID: 15663256
    Microsatellite primers are often developed in one species and used to assess neutral variability in related species. Such analyses may be confounded by ascertainment bias (i.e. a decline in amplification success and allelic variability with increasing genetic distance from the source of the microsatellites). In addition, other factors, such as the size of the microsatellite, whether it consists of perfect or interrupted tandem repeats, and whether it is autosomal or X-linked, can affect variation. To test the relative importance of these factors on microsatellite variation, we examine patterns of amplification and allelic diversity in 52 microsatellite loci amplified from five individuals in each of six populations of Cyrtodiopsis stalk-eyed flies that range from 2.2 % to 11.2% mitochondrial DNA sequence divergence from the population used for microsatellite development. We find that amplification success and most measures of allelic diversity declined with genetic distance from the source population, in some cases an order of magnitude faster than in birds or mammals. The median and range of the repeat array length did not decline with genetic distance. In addition, for loci on the X chromosome, we find evidence of lower observed heterozygosity compared with loci on autosomes. The differences in variability between X-linked and autosomal loci are not adequately explained by differences in effective population sizes of the chromosomes. We suggest, instead, that periodic selection events associated with X-chromosome meiotic drive, which is present in many of these populations, reduces X-linked variation.
    Matched MeSH terms: Genetic Variation*
  16. Tan MP, Jamsari AF, Siti Azizah MN
    J Fish Biol, 2016 May;88(5):1932-48.
    PMID: 27027270 DOI: 10.1111/jfb.12956
    Genetic variability and differences in wild striped snakehead Channa striata from Malaysia were analysed by genotyping nine novel nuclear microsatellite loci. Analysis revealed moderate-to-high genetic diversity in most of the populations, indicative of large effective population sizes. The highly diversified populations are admixed populations and, therefore, can be recommended as potential candidates for selective breeding and conservation since they each contain most of the alleles found in their particular region. Three homogenous groups of the wild populations were identified, apparently separated by effective barriers, in accordance with contemporary drainage patterns. The highest population pairwise FST found between members of the same group reflects the ancient population connectivity; yet prolonged geographical isolation resulted in adaptation of alleles to local contemporary environmental change. A significant relationship between genetic distance and geographical isolation was observed (r = 0·644, P < 0·01). Anthropogenic perturbations indicated apparent genetic proximity between distant populations.
    Matched MeSH terms: Genetic Variation*
  17. Tuhina-Khatun M, Hanafi MM, Rafii Yusop M, Wong MY, Salleh FM, Ferdous J
    Biomed Res Int, 2015;2015:290861.
    PMID: 26258135 DOI: 10.1155/2015/290861
    Upland rice is important for sustainable crop production to meet future food demands. The expansion in area of irrigated rice faces limitations due to water scarcity resulting from climate change. Therefore, this research aimed to identify potential genotypes and suitable traits of upland rice germplasm for breeding programmes. Forty-three genotypes were evaluated in a randomised complete block design with three replications. All genotypes exhibited a wide and significant variation for 22 traits. The highest phenotypic and genotypic coefficient of variation was recorded for the number of filled grains/panicle and yields/plant (g). The highest heritability was found for photosynthetic rate, transpiration rate, stomatal conductance, intercellular CO₂, and number of filled grains/panicle and yields/plant (g). Cluster analysis based on 22 traits grouped the 43 rice genotypes into five clusters. Cluster II was the largest and consisted of 20 genotypes mostly originating from the Philippines. The first four principle components of 22 traits accounted for about 72% of the total variation and indicated a wide variation among the genotypes. The selected best trait of the number of filled grains/panicle and yields/plant (g), which showed high heritability and high genetic advance, could be used as a selection criterion for hybridisation programmes in the future.
    Matched MeSH terms: Genetic Variation*
  18. Fong MY, Rashdi SA, Yusof R, Lau YL
    Malar J, 2015;14:91.
    PMID: 25890095 DOI: 10.1186/s12936-015-0610-x
    Plasmodium knowlesi is one of the monkey malaria parasites that can cause human malaria. The Duffy binding protein of P. knowlesi (PkDBPαII) is essential for the parasite's invasion into human and monkey erythrocytes. A previous study on P. knowlesi clinical isolates from Peninsular Malaysia reported high level of genetic diversity in the PkDBPαII. Furthermore, 36 amino acid haplotypes were identified and these haplotypes could be separated into allele group I and allele group II. In the present study, the PkDBPαII of clinical isolates from the Malaysian states of Sarawak and Sabah in North Borneo was investigated, and compared with the PkDBPαII of Peninsular Malaysia isolates.
    Matched MeSH terms: Genetic Variation*
  19. Scheltinga SA, van der Zwan AW, Mongkolsuk T, Sujirachato K, Chiewsilp P, Tilanus MG
    Tissue Antigens, 1999 May;53(5):507-9.
    PMID: 10372546
    Southern Thai Muslims (STM)--from Nakon Si Thammarat, whose ancestors come mainly from Malaysia--constitute more than half of all Thai Muslims which, in total, represent approximately 10% of the country's population. The most common A2 subtypes in STM were A*0203 (n=15), A*0201 (n=8) and A*0207 (n=7). In this study, samples with unexpected amplification patterns were sequenced. Three individuals were indicative of a novel A2 allele, now known as A*02012.
    Matched MeSH terms: Genetic Variation*
  20. Harada K, Kinoshita A, Shukor NA, Tachida H, Yamazaki T
    Jpn. J. Genet., 1994 Dec;69(6):713-8.
    PMID: 7857675
    Three species of Shorea (S. leprosula, S. acuminata and S. cursitii) were collected from a natural forest reserve of Malaysia and analyzed for genetic variation using the technique of random amplification of polymorphic DNA (RAPD) by the polymerase chain reaction (PCR). The average number of nucleotide substitutions was estimated. The nucleotide diversities within species were very similar and larger than those found in Drosophila melanogaster. The nucleotide divergences between these species are about 1.5 times the nucleotide diversities within the species, indicating that these species diverged from a common ancestor relatively recently.
    Matched MeSH terms: Genetic Variation*
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