Displaying publications 1 - 20 of 102 in total

  1. Liew KJ, Teo SC, Shamsir MS, Goh KM
    Microbiol Resour Announc, 2019 Nov 14;8(46).
    PMID: 31727717 DOI: 10.1128/MRA.01238-19
    Longimonas halophila and Longibacter salinarum are type strains of underexplored genera affiliated with Salisaetaceae Herein, we report the draft genome sequences of two strains of these bacteria, L. halophila KCTC 42399 and L. salinarum KCTC 52045, with the intent of broadening knowledge of this family. Genome annotation and gene mining revealed that both bacteria exhibit amylolytic abilities.
    Matched MeSH terms: Chromosome Mapping
  2. Ho WK, Chai HH, Kendabie P, Ahmad NS, Jani J, Massawe F, et al.
    BMC Genomics, 2017 02 20;18(1):192.
    PMID: 28219341 DOI: 10.1186/s12864-016-3393-8
    BACKGROUND: Bambara groundnut [Vigna subterranea (L) Verdc.] is an indigenous legume crop grown mainly in subsistence and small-scale agriculture in sub-Saharan Africa for its nutritious seeds and its tolerance to drought and poor soils. Given that the lack of ex ante sequence is often a bottleneck in marker-assisted crop breeding for minor and underutilised crops, we demonstrate the use of limited genetic information and resources developed within species, but linked to the well characterised common bean (Phaseolus vulgaris) genome sequence and the partially annotated closely related species; adzuki bean (Vigna angularis) and mung bean (Vigna radiata). From these comparisons we identify conserved synteny blocks corresponding to the Linkage Groups (LGs) in bambara groundnut genetic maps and evaluate the potential to identify genes in conserved syntenic locations in a sequenced genome that underlie a QTL position in the underutilised crop genome.

    RESULTS: Two individual intraspecific linkage maps consisting of DArTseq markers were constructed in two bambara groundnut (2n = 2x = 22) segregating populations: 1) The genetic map of Population IA was derived from F2lines (n = 263; IITA686 x Ankpa4) and covered 1,395.2 cM across 11 linkage groups; 2) The genetic map of Population TD was derived from F3lines (n = 71; Tiga Nicuru x DipC) and covered 1,376.7 cM across 11 linkage groups. A total of 96 DArTseq markers from an initial pool of 142 pre-selected common markers were used. These were not only polymorphic in both populations but also each marker could be located using the unique sequence tag (at selected stringency) onto the common bean, adzuki bean and mung bean genomes, thus allowing the sequenced genomes to be used as an initial 'pseudo' physical map for bambara groundnut. A good correspondence was observed at the macro synteny level, particularly to the common bean genome. A test using the QTL location of an agronomic trait in one of the bambara groundnut maps allowed the corresponding flanking positions to be identified in common bean, mung bean and adzuki bean, demonstrating the possibility of identifying potential candidate genes underlying traits of interest through the conserved syntenic physical location of QTL in the well annotated genomes of closely related species.

    CONCLUSIONS: The approach of adding pre-selected common markers in both populations before genetic map construction has provided a translational framework for potential identification of candidate genes underlying a QTL of trait of interest in bambara groundnut by linking the positions of known genetic effects within the underutilised species to the physical maps of other well-annotated legume species, without the need for an existing whole genome sequence of the study species. Identifying the conserved synteny between underutilised species without complete genome sequences and the genomes of major crops and model species with genetic and trait data is an important step in the translation of resources and information from major crop and model species into the minor crop species. Such minor crops will be required to play an important role in future agriculture under the effects of climate change.

    Matched MeSH terms: Chromosome Mapping*
  3. Gan HM, Lee MVJ, Savka MA
    Microbiol Resour Announc, 2018 Sep;7(9).
    PMID: 30533933 DOI: 10.1128/MRA.01045-18
    Using Illumina and Nanopore reads, we assembled a high-quality draft genome sequence of Allorhizobium vitis K309T (= ATCC 49767T, = NCPPB 3554T), a phytopathogenic strain isolated from a grapevine in Australia. The hybrid approach generated 50% fewer contigs and a 3-fold increase in the N50 value compared with the previous Illumina-only assembly.
    Matched MeSH terms: Chromosome Mapping
  4. Too CC, Ong KS, Lee SM, Yule CM, Keller A
    Microbiol Resour Announc, 2018 Sep;7(12).
    PMID: 30533674 DOI: 10.1128/MRA.01083-18
    The bacterium Dyella sp. strain C9 was isolated from North Selangor Peat Swamp Forest, Malaysia, and studied using whole-genome sequencing. The putative genes involved in biogeochemical processes were annotated, and the genome sequence is publicly available in the NCBI database.
    Matched MeSH terms: Chromosome Mapping
  5. Too CC, Ong KS, Lee SM, Yule CM, Keller A
    Genome Announc, 2018 Jun 21;6(25).
    PMID: 29930031 DOI: 10.1128/genomeA.00459-18
    We report here the draft genome sequences of a bacterial isolate, Dyella sp. strain C11, which was isolated from a Malaysian tropical peat swamp forest. The putative genes for the biogeochemical processes were annotated, and the genome was deposited in an online database.
    Matched MeSH terms: Chromosome Mapping
  6. Too CC, Ong KS, Ankenbrand MJ, Lee SM, Yule CM, Keller A
    Genome Announc, 2018 Jun 21;6(25).
    PMID: 29930066 DOI: 10.1128/genomeA.00561-18
    We report the draft genome sequence of a bacterial isolate, Paraburkholderia sp. strain C35, which was isolated from a Malaysian tropical peat swamp forest. The putative genes for the biogeochemical processes were annotated and are publicly available in the online databases.
    Matched MeSH terms: Chromosome Mapping
  7. Sam KK, Lau NS, Furusawa G, Amirul AA
    Microbiol Resour Announc, 2019 Nov 14;8(46).
    PMID: 31727719 DOI: 10.1128/MRA.01248-19
    Pararhodobacter-like strain CCB-MM2 is a halophilic alphaproteobacterium isolated from estuarine sediment collected from Matang Mangrove Forest in Malaysia. Here, we present the draft genome sequence of CCB-MM2 and provide insights into its physiological roles and metabolic potential.
    Matched MeSH terms: Chromosome Mapping
  8. Ashkani S, Rafii MY, Shabanimofrad M, Ghasemzadeh A, Ravanfar SA, Latif MA
    Crit. Rev. Biotechnol., 2016;36(2):353-67.
    PMID: 25394538 DOI: 10.3109/07388551.2014.961403
    Rice blast disease, which is caused by the fungal pathogen Magnaporthe oryzae, is a recurring problem in all rice-growing regions of the world. The use of resistance (R) genes in rice improvement breeding programmes has been considered to be one of the best options for crop protection and blast management. Alternatively, quantitative resistance conferred by quantitative trait loci (QTLs) is also a valuable resource for the improvement of rice disease resistance. In the past, intensive efforts have been made to identify major R-genes as well as QTLs for blast disease using molecular techniques. A review of bibliographic references shows over 100 blast resistance genes and a larger number of QTLs (∼500) that were mapped to the rice genome. Of the blast resistance genes, identified in different genotypes of rice, ∼22 have been cloned and characterized at the molecular level. In this review, we have summarized the reported rice blast resistance genes and QTLs for utilization in future molecular breeding programmes to introgress high-degree resistance or to pyramid R-genes in commercial cultivars that are susceptible to M. oryzae. The goal of this review is to provide an overview of the significant studies in order to update our understanding of the molecular progress on rice and M. oryzae. This information will assist rice breeders to improve the resistance to rice blast using marker-assisted selection which continues to be a priority for rice-breeding programmes.
    Matched MeSH terms: Chromosome Mapping*
  9. 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: Chromosome Mapping*
  10. Keong BP, Siraj SS, Daud SK, Panandam JM, Rahman AN
    Gene, 2014 Feb 15;536(1):114-7.
    PMID: 24333858 DOI: 10.1016/j.gene.2013.11.068
    A preliminary linkage map was constructed by applying backcross and testcross strategy using microsatellite (SSR) markers developed for Xiphophorus and Poecilia reticulata in ornamental fish, molly Poecilia sp. The linkage map having 18 SSR loci consisted of four linkage groups that spanned a map size of 516.1cM. Association between genotypes and phenotypes was tested in a random fashion and QTL for dorsal fin length was found to be linked to locus Msb069 on linkage group 2. Coincidentally, locus Msb069 was also reported as putative homologue primer pairs containing SSRs repeat motif which encoded hSMP-1, a sex determining locus. Dorsal fin length particularly in males of Poecilia latipinna is an important feature during courtship display. Therefore, we speculate that both dorsal fin length and putative hSMP-1 gene formed a close proximity to male sexual characteristics.
    Matched MeSH terms: Chromosome Mapping/methods; Chromosome Mapping/veterinary
  11. Chua, B. H., Rajinder, S., Tan, S. G., Faridah, Q. Z., Cheah, S. C.
    Microsatellites or simple sequence repeats (SSRs) are tandem repeats of DNA of 1-6 bp long. They ubiquitously occur in both eukaryotic and prokaryotic genomes. Because of their abundance,
    they have widespread applications in both animal and plant sciences; such as varietal identification, genetic mapping, QTL mapping, phylogenetic and diversity studies. Thus, SSRs have become valuable DNA markers for molecular biologists and geneticists. Microsatellites are markers
    of choice for many molecular geneticists because of their hypervariability, codominant
    inheritance, multi-allelism and PCR-based assaying of variations that are amenable to automation and high throughput assay. However, the utilization of microsatellite markers in the past was
    hampered by its laborious de novo isolations and species-specific nature.
    Matched MeSH terms: Chromosome Mapping
  12. Ngu MS, Thomson MJ, Bhuiyan MA, Ho C, Wickneswari R
    Genet. Mol. Res., 2014;13(4):9477-88.
    PMID: 25501158 DOI: 10.4238/2014.November.11.13
    Grain weight is a major component of rice grain yield and is controlled by quantitative trait loci. Previously, a rice grain weight quantitative trait locus (qGW6) was detected near marker RM587 on chromosome 6 in a backcross population (BC2F2) derived from a cross between Oryza rufipogon IRGC105491 and O. sativa cv. MR219. Using a BC2F5 population, qGW6 was validated and mapped to a region of 4.8 cM (1.2 Mb) in the interval between RM508 and RM588. Fine mapping using a series of BC4F3 near isogenic lines further narrowed the interval containing qGW6 to 88 kb between markers RM19268 and RM19271.1. According to the Duncan multiple range test, 8 BC4F4 near isogenic lines had significantly higher 100-grain weight (4.8 to 7.5% over MR219) than their recurrent parent, MR219 (P < 0.05). According to the rice genome automated annotation database, there are 20 predicted genes in the 88-kb target region, and 9 of them have known functions. Among the genes with known functions in the target region, in silico gene expression analysis showed that 9 were differentially expressed during the seed development stage(s) from gene expression series GSE6893; however, only 3 of them have known functions. These candidates provide targets for further characterization of qGW6, which will assist in understanding the genetic control of grain weight in rice.
    Matched MeSH terms: Physical Chromosome Mapping*
  13. Lau YY, Yin WF, Chan KG
    Sensors (Basel), 2014;14(8):13913-24.
    PMID: 25196111 DOI: 10.3390/s140813913
    Enterobacter asburiae L1 is a quorum sensing bacterium isolated from lettuce leaves. In this study, for the first time, the complete genome of E. asburiae L1 was sequenced using the single molecule real time sequencer (PacBio RSII) and the whole genome sequence was verified by using optical genome mapping (OpGen) technology. In our previous study, E. asburiae L1 has been reported to produce AHLs, suggesting the possibility of virulence factor regulation which is quorum sensing dependent. This evoked our interest to study the genome of this bacterium and here we present the complete genome of E. asburiae L1, which carries the virulence factor gene virK, the N-acyl homoserine lactone-based QS transcriptional regulator gene luxR and the N-acyl homoserine lactone synthase gene which we firstly named easI. The availability of the whole genome sequence of E. asburiae L1 will pave the way for the study of the QS-mediated gene expression in this bacterium. Hence, the importance and functions of these signaling molecules can be further studied in the hope of elucidating the mechanisms of QS-regulation in E. asburiae. To the best of our knowledge, this is the first documentation of both a complete genome sequence and the establishment of the molecular basis of QS properties of E. asburiae.
    Matched MeSH terms: Chromosome Mapping/methods
  14. Ting NC, Jansen J, Mayes S, Massawe F, Sambanthamurthi R, Ooi LC, et al.
    BMC Genomics, 2014;15:309.
    PMID: 24767304 DOI: 10.1186/1471-2164-15-309
    Oil palm is an important perennial oil crop with an extremely long selection cycle of 10 to 12 years. As such, any tool that speeds up its genetic improvement process, such as marker-assisted breeding is invaluable. Previously, genetic linkage maps based on AFLP, RFLP and SSR markers were developed and QTLs for fatty acid composition and yield components identified. High density genetic maps of crosses of different genetic backgrounds are indispensable tools for investigating oil palm genetics. They are also useful for comparative mapping analyses to identify markers closely linked to traits of interest.
    Matched MeSH terms: Chromosome Mapping*
  15. Ashkani S, Rafii MY, Rahim HA, Latif MA
    Biotechnol. Lett., 2013 May;35(5):799-810.
    PMID: 23315158 DOI: 10.1007/s10529-012-1130-1
    Malaysian rice, Pongsu Seribu 2, has wide-spectrum resistance against blast disease. Chromosomal locations conferring quantitative resistance were detected by linkage mapping with SSRs and quantitative trait locus (QTL) analysis. For the mapping population, 188 F3 families were derived from a cross between the susceptible cultivar, Mahsuri, and a resistant variety, Pongsu Seribu 2. Partial resistance to leaf blast in the mapping population was assessed. A linkage map covering ten chromosomes and consisting of 63 SSR markers was constructed. 13 QTLs, including 6 putative and 7 putative QTLs, were detected on chromosomes 1, 2, 3, 5, 6, 10, 11 and 12. The resulting phenotypic variation due to a single QTL ranged from 2 to 13 %. These QTLs accounted for approx. 80 % of the total phenotypic variation within the F3 population. Therefore, partial resistance to blast in Pongsu Seribu 2 is due to combined effects of multiple loci with major and minor effects.
    Matched MeSH terms: Chromosome Mapping/methods*
  16. Ashkani S, Rafii MY, Rahim HA, Latif MA
    Mol. Biol. Rep., 2013 Mar;40(3):2503-15.
    PMID: 23203411 DOI: 10.1007/s11033-012-2331-3
    Rice blast is one of the major fungal diseases that badly reduce rice production in Asia including Malaysia. There is not much information on identification of QTLs as well as linked markers and their association with blast resistance within local rice cultivars. In order to understanding of the genetic control of blast in the F3 families from indica rice cross Pongsu seribu2/Mahsuri, an analysis of quantitative trait loci against one of the highly virulent Malaysian rice blast isolate Magnaporthe oryzae, P5.0 was carried out. Result indicated that partial resistance to this pathotype observed in the present study was controlled by multiple loci or different QTLs. In QTL analysis in F3 progeny fifteen QTLs on chromosomes 1, 2, 3, 5, 6, 11 and 12 for resistance to blast nursery tests was identified. Three of detected QTLs (qRBr-6.1, qRBr-11.4, and qRBr-12.1) had significant threshold (LOD >3) and approved by both IM and CIM methods. Twelve suggestive QTLs, qRBr-1.2, qRBr-2.1, qRBr-4.1, qRBr-5.1, qRBr-6.2, qRBr-6.3, qRBr-8.1, qRBr-10.1, qRBr-10.2, qRBr-11.1, qRBr-11.2 and qRBr-11.3) with Logarithmic of Odds (LOD) <3.0 or LRS <15) were distributed on chromosomes 1, 2, 4, 5, 6, 8, 10, and 11. Most of the QTLs detected using single isolate had the resistant alleles from Pongsu seribu 2 which involved in the resistance in the greenhouse. We found that QTLs detected for deferent traits for the using isolate were frequently located in similar genomic regions. Inheritance study showed among F3 lines resistance segregated in the expected ratio of 15: 1 for resistant to susceptible. The average score for blast resistance measured in the green house was 3.15, 1.98 and 29.95 % for three traits, BLD, BLT and % DLA, respectively.
    Matched MeSH terms: Chromosome Mapping*
  17. Lie-Injo LE, Pawson IG, Solai A
    Hum. Genet., 1985;70(2):116-8.
    PMID: 2989152
    Most of the population in certain areas of Melanesia have one alpha-globin gene deletion (alpha thal2). It is thought that the high frequencies of alpha thal2 in this population is due to a selective advantage given by malaria infection to carriers of alpha thal2. We are interested in neighboring Polynesia which, although adjacent to Melanesia, has always been free of malaria due to the absence of the vector anopheles. We studied 60 Polynesian Samoans and 150 Malaysians by restriction endonuclease gene mapping using Eco RI, Bam HI, and Bgl II and hybridization to 32P-labeled alpha-globin gene probe. Seven among the 60 (11.7%) Samoans had triplicated alpha-globin loci type 1, while none had alpha thal2. On digestion with Bgl II the third alpha-globin gene was found in an additional 3.7 kb fragment in all seven Samoans with triplicated alpha-globin loci, while digestion with Bam HI produced an abnormal elongated 18.2 kb fragment carrying alpha-globin genes in addition to the normal 14.5 kb fragment. None of the Polynesian Samoans had alpha thal2 or alpha thal1. Only two of the Malaysians had triplicated alpha-globin loci.
    Matched MeSH terms: Chromosome Mapping*
  18. Wong CK, Bernardo R
    Theor. Appl. Genet., 2008 Apr;116(6):815-24.
    PMID: 18219476 DOI: 10.1007/s00122-008-0715-5
    Oil palm (Elaeis guineensis Jacq.) requires 19 years per cycle of phenotypic selection. The use of molecular markers may reduce the generation interval and the cost of oil-palm breeding. Our objectives were to compare, by simulation, the response to phenotypic selection, marker-assisted recurrent selection (MARS), and genomewide selection with small population sizes in oil palm, and assess the efficiency of each method in terms of years and cost per unit gain. Markers significantly associated with the trait were used to calculate the marker scores in MARS, whereas all markers were used (without significance tests) to calculate the marker scores in genomewide selection. Responses to phenotypic selection and genomewide selection were consistently greater than the response to MARS. With population sizes of N = 50 or 70, responses to genomewide selection were 4-25% larger than the corresponding responses to phenotypic selection, depending on the heritability and number of quantitative trait loci. Cost per unit gain was 26-57% lower with genomewide selection than with phenotypic selection when markers cost US $1.50 per data point, and 35-65% lower when markers cost $0.15 per data point. With population sizes of N = 50 or 70, time per unit gain was 11-23 years with genomewide selection and 14-25 years with phenotypic selection. We conclude that for a realistic yet relatively small population size of N = 50 in oil palm, genomewide selection is superior to MARS and phenotypic selection in terms of gain per unit cost and time. Our results should be generally applicable to other tree species that are characterized by long generation intervals, high costs of maintaining breeding plantations, and small population sizes in selection programs.
    Matched MeSH terms: Chromosome Mapping*
  19. Ferdig MT, Taft AS, Severson DW, Christensen BM
    Genome Res., 1998 Jan;8(1):41-7.
    PMID: 9445486
    One of the causative agents of lympahtic filariasis is the nematode parasite Brugia malayi that requires a competent mosquito vector for its development and transmission. Armigeres subalbatus mosquitoes rapidly destroy invading B. malayi microfilariae via a defense response known as melanotic encapsulation. We have constructed a genetic linkage map for this mosquito species using RFLP markers from Aedes aegypti. This heterologous approach was possible because of the conserved nature of the coding sequences used as markers and provided an experimental framework to evaluate the hypothesis that linkage and gene order are conserved between these mosquito species. Of the 56 Ae. aegypti markers tested, 77% hybridize to genomic DNA digests of Ar. subalbatus under stringent conditions, with 53% of these demonstrating strain-specific polymorphisms. Twenty-six Ae. aegypti markers have been mapped using an F2- segregating Ar. subalbatus population derived from a cross of strains originating in Japan and Malaysia. Linear order of these marker loci is highly conserved between the two species. Only 1 of these markers, LF92, was not linked in the manner predicted by the Ae. aegypti map. In addition, the autosomal sex-determination locus that occurs in linkage group 1 in Ae. aegypti resides in group 3 in Ar. subalbatus. The Ar. subalbatus map provides a basic genetic context that can be utilized in further genetic studies to clarify the genetic basis of parasite resistance in this mosquito and is a necessary precursor to the identification of genome regions that carry genes that determine the encapsulation phenotype. [The composite map and sequence database information for Ae. aegypti markers can be retrieved directly from the Ae. aegypti Genome Database through the World Wide Web: http://klab.agsci.colostate.edu.]
    Matched MeSH terms: Chromosome Mapping/methods*
  20. Seng TY, Mohamed Saad SH, Chin CW, Ting NC, Harminder Singh RS, Qamaruz Zaman F, et al.
    PLoS ONE, 2011;6(11):e26593.
    PMID: 22069457 DOI: 10.1371/journal.pone.0026593
    Enroute to mapping QTLs for yield components in oil palm, we constructed the linkage map of a FELDA high yielding oil palm (Elaeis guineensis), hybrid cross. The parents of the mapping population are a Deli dura and a pisifera of Yangambi origin. The cross out-yielded the average by 8-21% in four trials all of which yielded comparably to the best current commercial planting materials. The higher yield derived from a higher fruit oil content. SSR markers in the public domain - from CIRAD and MPOB, as well as some developed in FELDA - were used for the mapping, augmented by locally-designed AFLP markers. The female parent linkage map comprised 317 marker loci and the male parent map 331 loci, both in 16 linkage groups each. The number of markers per group ranged from 8-47 in the former and 12-40 in the latter. The integrated map was 2,247.5 cM long and included 479 markers and 168 anchor points. The number of markers per linkage group was 15-57, the average being 29, and the average map density 4.7 cM. The linkage groups ranged in length from 77.5 cM to 223.7 cM, with an average of 137 cM. The map is currently being validated against a closely related population and also being expanded to include yield related QTLs.
    Matched MeSH terms: Chromosome Mapping*
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