Displaying publications 81 - 100 of 250 in total

Abstract:
Sort:
  1. Development of microsatellite markers in Gonystylus bancanus (Ramin) useful for tracing and tracking of wood of this protected species
    Smulders MJ, VAN 't Westende WP, Diway B, Esselink GD, VAN DER Meer PJ, Koopman WJ
    Mol Ecol Resour, 2008 Jan;8(1):168-71.
    PMID: 21585747 DOI: 10.1111/j.1471-8286.2007.01914.x
    Ten polymorphic microsatellite markers have been developed for Gonystylus bancanus (Ramin), a protected tree species of peat swamp forests in Malaysia and Indonesia. Eight markers were also shown to be polymorphic in other Gonystylus species. The markers will enable assessing the amount of genetic variation within and among populations and the degree of population differentiation, such that donor populations can be selected for reforestation projects. They may be used for tracing and tracking of wood in the production chain, so that legal trade in this Convention on International Trade in Endangered Species of Wild Fauna and Flora-protected timber species, derived from specifically described origins, can be distinguished from illegally logged timber.
    Matched MeSH terms: Microsatellite Repeats
  2. Fulltext Genetic differentiation and phylogeography of partially sympatric species complex Rhizophora mucronata Lam. and R. stylosa Griff. using SSR markers
    Wee AK, Takayama K, Chua JL, Asakawa T, Meenakshisundaram SH, Onrizal, et al.
    BMC Evol. Biol., 2015 Mar 29;15:57.
    PMID: 25888261 DOI: 10.1186/s12862-015-0331-3
    BACKGROUND: Mangrove forests are ecologically important but globally threatened intertidal plant communities. Effective mangrove conservation requires the determination of species identity, management units, and genetic structure. Here, we investigate the genetic distinctiveness and genetic structure of an iconic but yet taxonomically confusing species complex Rhizophora mucronata and R. stylosa across their distributional range, by employing a suite of 20 informative nuclear SSR markers.

    RESULTS: Our results demonstrated the general genetic distinctiveness of R. mucronata and R. stylosa, and potential hybridization or introgression between them. We investigated the population genetics of each species without the putative hybrids, and found strong genetic structure between oceanic regions in both R. mucronata and R. stylosa. In R. mucronata, a strong divergence was detected between populations from the Indian Ocean region (Indian Ocean and Andaman Sea) and the Pacific Ocean region (Malacca Strait, South China Sea and Northwest Pacific Ocean). In R. stylosa, the genetic break was located more eastward, between populations from South and East China Sea and populations from the Southwest Pacific Ocean. The location of these genetic breaks coincided with the boundaries of oceanic currents, thus suggesting that oceanic circulation patterns might have acted as a cryptic barrier to gene flow.

    CONCLUSIONS: Our findings have important implications on the conservation of mangroves, especially relating to replanting efforts and the definition of evolutionary significant units in Rhizophora species. We outlined the genetic structure and identified geographical areas that require further investigations for both R. mucronata and R. stylosa. These results serve as the foundation for the conservation genetics of R. mucronata and R. stylosa and highlighted the need to recognize the genetic distinctiveness of closely-related species, determine their respective genetic structure, and avoid artificially promoting hybridization in mangrove restoration programmes.

    Matched MeSH terms: Microsatellite Repeats
  3. Estimation of gene flow in the tropical-rainforest tree Neobalanocarpus heimii (Dipterocarpaceae), inferred from paternity analysis
    Konuma A, Tsumura Y, Lee CT, Lee SL, Okuda T
    Mol Ecol, 2000 Nov;9(11):1843-52.
    PMID: 11091320
    Pollen flow and population genetic structure among 30 potentially flowering individuals of Neobalanocarpus heimii, a tropical emergent tree, were investigated in a lowland tropical rainforest of Malaysia using microsatellite polymorphism. The 248 offspring in the vicinity of five reproductive trees of the 30 potentially flowering trees were used in paternity analysis for pollen-flow study. Four primer pairs, developed in different species of dipterocarps, were adopted to detect microsatellite polymorphism. Based upon microsatellite polymorphism, pollen flow and seed migration were detected. Pollen-flow events of more than 400 m were observed directly, based on paternity analysis in the study plot. The estimated average mating distance of the five reproductive trees was 524 m. This result suggests that reproduction of this species is mediated by a long-distance pollinator. The haplotypes of some offspring were not compatible with the nearest reproductive tree. Thus, the results suggest that some seeds are dispersed by a seed dispersal vector. Investigation of genetic structure showed significant and negative correlation of genetic relatedness and spatial distances between the 30 potentially flowering trees, but this correlation was weak. We suggest that long-distance gene flow and seed migration are responsible for the poorly developed genetic structure of this species.
    Matched MeSH terms: Microsatellite Repeats
  4. Fulltext Development of novel microsatellite markers using RAD sequencing technology for diversity assessment of rambutan (Nephelium lappaceum L.) germplasm
    Ab Razak S, Mad Radzuan S, Mohamed N, Nor Azman NHE, Abd Majid AM, Ismail SN, et al.
    Heliyon, 2020 Sep;6(9):e05077.
    PMID: 33024864 DOI: 10.1016/j.heliyon.2020.e05077
    The trend of microsatellite marker discovery and development revolved as a result of the advancement of next generation sequencing (NGS) technology as it has developed numerous microsatellites within a short period of time at a low cost. This study generated microsatellite markers using RAD sequencing technologies for the understudied Nephelium lappaceum. A total of 1403 microsatellite markers were successfully designed, which consisted of 853 di-, 525 tri-, 17 tetra-, 5 penta-, and 3 hexanucleotide microsatellite markers. Subsequently, selection of 39 microsatellites was made for the evaluation of genetic diversity of the selected 22 rambutan varieties. Twelve microsatellites, which exhibited high call rates across the samples, were used to assess the diversity of the aforementioned rambutan varieties. The analysis of 12 microsatellites revealed the presence of 72 alleles and six alleles per locus in average. Furthermore, the polymorphic information content (PIC) value ranged from 0.326 (NlaSSR20) to 0.832 (NlaSSR32), which included an average of 0.629 per locus, while the generated Neighbour Joining dendrogram showed two major clusters. The pairwise genetic distance of shared alleles exhibited a range of values from 0.046 (R134↔R170) to 0.818 (R5↔R170), which suggested highest dissimilarity detected between R5 and R170. Notably, these research findings would useful for varietal identification, proper management and conservation of the genetic resources, and exploitation and utilization in future breeding programs.
    Matched MeSH terms: Microsatellite Repeats
  5. Fulltext In Silico Approach for Characterization and Comparison of Repeats in the Genomes of Oil and Date Palms
    Filho JAF, de Brito LS, Leão AP, Alves AA, Formighieri EF, Júnior MTS
    Bioinform Biol Insights, 2017;11:1177932217702388.
    PMID: 28469420 DOI: 10.1177/1177932217702388
    Transposable elements (TEs) are mobile genetic elements present in almost all eukaryotic genomes. Due to their typical patterns of repetition, discovery, and characterization, they demand analysis by various bioinformatics software. Probably, as a result of the need for a complex analysis, many genomes publicly available do not have these elements annotated yet. In this study, a de novo and homology-based identification of TEs and microsatellites was performed using genomic data from 3 palm species: Elaeis oleifera (American oil palm, v.1, Embrapa, unpublished; v.8, Malaysian Palm Oil Board [MPOB], public), Elaeis guineensis (African oil palm, v.5, MPOB, public), and Phoenix dactylifera (date palm). The estimated total coverage of TEs was 50.96% (523 572 kb) and 42.31% (593 463 kb), 39.41% (605 015 kb), and 33.67% (187 361 kb), respectively. A total of 155 726 microsatellite loci were identified in the genomes of oil and date palms. This is the first detailed description of repeats in the genomes of oil and date palms. A relatively high diversity and abundance of TEs were found in the genomes, opening a range of further opportunities for applied research in these genera. The development of molecular markers (mainly simple sequence repeat), which may be immediately applied in breeding programs of those species to support the selection of superior genotypes and to enhance knowledge of the genetic structure of the breeding and natural populations, is the most notable opportunity.
    Matched MeSH terms: Microsatellite Repeats
  6. Fulltext Cross-amplification of microsatellite markers across agarwood-producing species of the Aquilarieae tribe (Thymelaeaceae)
    Pern YC, Lee SY, Ng WL, Mohamed R
    3 Biotech, 2020 Mar;10(3):103.
    PMID: 32099744 DOI: 10.1007/s13205-020-2072-2
    Tree species in the Aquilarieae tribe of the Thymelaeaceae family produce agarwood, a natural product highly valued for its fragrance, but the species are under threat due to indiscriminate harvesting. For conservation of these species, molecular techniques such as DNA profiling have been used. In this study, we assessed cross-amplification of microsatellite markers, initially developed for three Aquilaria species (A.crassna, A.malaccensis, and A.sinensis), on ten other agarwood-producing species, including members of Aquilaria (A.beccariana, A.hirta, A.microcarpa, A.rostrata, A.rugosa, A.subintegra, and A.yunnanensis) and Gyrinops (G.caudata, G.versteegii, and G.walla), both from the Aquilarieae tribe. Primers for 18 out of the 30 microsatellite markers successfully amplified bands of expected sizes in 1 sample each of at least 10 species. These were further used to genotype 74 individuals representing all the 13 studied species, yielding 13 cross-amplifiable markers, of which only 1 being polymorphic across all species. At each locus, the number of alleles ranged from 7 to 23, indicating a rather high variability. Four markers had relatively high species discrimination power. Our results demonstrated that genetic fingerprinting can be an effective tool in helping to manage agarwood genetic resources by potentially supporting the chain-of-custody of agarwood and its products in the market.
    Matched MeSH terms: Microsatellite Repeats
  7. Fulltext PlantFuncSSR: Integrating First and Next Generation Transcriptomics for Mining of SSR-Functional Domains Markers
    Sablok G, Pérez-Pulido AJ, Do T, Seong TY, Casimiro-Soriguer CS, La Porta N, et al.
    Front Plant Sci, 2016;7:878.
    PMID: 27446111 DOI: 10.3389/fpls.2016.00878
    Analysis of repetitive DNA sequence content and divergence among the repetitive functional classes is a well-accepted approach for estimation of inter- and intra-generic differences in plant genomes. Among these elements, microsatellites, or Simple Sequence Repeats (SSRs), have been widely demonstrated as powerful genetic markers for species and varieties discrimination. We present PlantFuncSSRs platform having more than 364 plant species with more than 2 million functional SSRs. They are provided with detailed annotations for easy functional browsing of SSRs and with information on primer pairs and associated functional domains. PlantFuncSSRs can be leveraged to identify functional-based genic variability among the species of interest, which might be of particular interest in developing functional markers in plants. This comprehensive on-line portal unifies mining of SSRs from first and next generation sequencing datasets, corresponding primer pairs and associated in-depth functional annotation such as gene ontology annotation, gene interactions and its identification from reference protein databases. PlantFuncSSRs is freely accessible at: http://www.bioinfocabd.upo.es/plantssr.
    Matched MeSH terms: Microsatellite Repeats
  8. Genetic Diversity of Pineapple (Ananas comosus) Germplasm in Malaysia Using Simple Sequence Repeat (SSR) Markers
    Ismail SN, Ghani NSA, Ab Razak SF, Abidin RAZ, Mohd Yusof MF, Zubir MN, et al.
    Trop Life Sci Res, 2020 Oct;31(3):15-27.
    PMID: 33214853 DOI: 10.21315/tlsr2020.31.3.2
    Assessments of genetic diversity have been claimed to be significantly efficient in utilising and managing resources of genetic for breeding programme. In this study, variations in genetic were observed in 65 pineapple accessions gathered from germplasm available at Malaysian Agriculture Research and Development Institute (MARDI) located in Pontian, Johor via 15 markers of simple sequence repeat (SSR). The results showed that 59 alleles appeared to range from 2.0 to 6.0 alleles with a mean of 3.9 alleles per locus, thus displaying polymorphism for all samples at a moderate level. Furthermore, the values of polymorphic information content (PIC) had been found to range between 0.104 (TsuAC035) and 0.697 (Acom_9.9), thus averaging at the value of 0.433. In addition, the expected and the observed heterozygosity of each locus seemed to vary within the ranges of 0.033 to 0.712, and from 0.033 to 0.885, along with the average values of 0.437 and 0.511, respectively. The population structure analysis via method of delta K (ΔK), along with mean of L (K) method, revealed that individuals from the germplasm could be divided into two major clusters based on genetics (K = 2), namely Group 1 and Group 2. As such, five accessions (Yankee, SRK Chalok, SCK Giant India, SC KEW5 India and SC1 Thailand) were clustered in Group 1, while the rest were clustered in Group 2. These outcomes were also supported by the dendrogram, which had been generated through the technique of unweighted pair group with arithmetic mean (UPGMA). These analyses appear to be helpful amongst breeders to maintain and to manage their collections of germplasm. Besides, the data gathered in this study can be useful for breeders to exploit the area of genetic diversity in estimating the level of heterosis.
    Matched MeSH terms: Microsatellite Repeats
  9. Fulltext Isolation and optimization of inter-simple sequence repeat (issr) technique for pleurotus sajor caju towards enviromental study in support of the country’s nuclear power programme
    Rosnani Abdul Rashid, Azhar Mohamad, Mat Rasol Awang, Hassan Hamdani Mutaat, Shaiful Azuar Mohamad, Affrida Abu Hasan, et al.
    Jurnal Sains Nuklear Malaysia, 2013;25(1):1-18.
    MyJurnal
    Mushroom can be used as a biological indicator in assessing radiological impact on the
    environment. Radiological effect would be reflected through morphological changes as well as
    those changes at molecular level. For this purpose, a preliminary work was conducted, which
    included DNA isolation, optimization of PCR parameters for Inter-Simple Sequence Repeat (ISSR)
    and primers screening on Pleurotus sajor caju mushroom strains from Nuclear Malaysia’s
    Sterifeed Mushrooms Collection Centre. In this work, DNA isolation technique from cap and stalk
    of fruit body were optimized and quantified. It was found that stalk produced highest amount of
    genomic DNA at 304.01ng/µl and cap at 149.00ng/µl. A total of 100 ISSR primers were tested and
    51 primers were successfully amplified. These primers will be used further for dose response
    evaluation and molecular profiling in mushroom species.
    Matched MeSH terms: Microsatellite Repeats
  10. Fulltext Dataset of SSR markers for ISSR-Suppression-PCR to detect genetic variation in Garcinia mangostana L. in Peninsular Malaysia
    Samsir SA, Bunawan H, Yen CC, Noor NM
    Data Brief, 2016 Sep;8:1438-42.
    PMID: 27617279 DOI: 10.1016/j.dib.2016.08.016
    In this dataset, we present 15 Simple Sequence Repeat (SSR) markers with the motifs (AC)n, (GA)n, and (AC)n(AG)n using a ISSR-Suppression-PCR technique in order to discriminate Garcinia mangostana from diverse geographical origins in Peninsular Malaysia. A few loci showed differences between 3 and 6 bp in allele size, indicating that there are some polymorphisms between individuals correlating to the number of SSR repeats that may be useful for differentiate of genotypes. Collectively, these data show that the ISSR-Suppression-PCR is a valuable method to illustrate genetic variation of selected G. mangostana in Malaysia.
    Matched MeSH terms: Microsatellite Repeats
  11. Fulltext Oil palm microsatellites: implications and potentials
    Chua, B. H., Rajinder, S., Tan, S. G., Faridah, Q. Z., Cheah, S. C.
    Buletin Persatuan Genetik Malaysia, 2006;12(1):1-5.
    MyJurnal
    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: Microsatellite Repeats
  12. Microsatellite DYS385 polymorphism among the Tai and Mon-Khmer speaking populations of Northern Thailand
    Jatupol Kampuansai, Siriwadee Chomdej
    Sains Malaysiana, 2015;44:1453-1459.
    Microsatellite DYS385 is a highly polymorphic marker in the Y chromosome. It has been used for investigating population genetic structure and personal identification in various ethnic groups of the world. This research aimed to analyze the microsatellite DYS385 polymorphism among 9 Tai and 11 Mon-Khmer speaking populations of northern Thailand. Fiftysix different haplotypes were found in 453 samples from 20 populations. Haplotype diversities and discrimination powers of populations belonging to the Tai linguistic family was higher than those of the Mon-Khmer group. Genetic affinities based on DYS385 variation do not conform to linguistic classification but a fraction of genetic divergence patterns can be explained by geographic distances.
    Matched MeSH terms: Microsatellite Repeats
  13. Development and characterization of elaeis oleifera microsatellite markers
    Noorhariza Mohd Zaki, Rozana Rosli, Ting NC, Singh R, Ismanizan Ismail
    Sains Malaysiana, 2010;39.
    Ten Elaeis oleifera microsatellite markers were developed and characterised from 1500 sequences of the E. oleifera genomic library. The markers were utilised to assess the genetic diversity of E. oleifera germplasm collections from four South American countries (Colombia, Costa Rica, Panama and Honduras). The number of alleles per-locus varied from 2 to 11 and the observed and expected heterozygosity ranged from 0.0685 to 0.9853 and 0.1393 to 0.8216 respectively. Majority of the markers showed transferability to Elaeis guineensis while two markers showed transferability across Arecaceae taxa. These E. oleifera microsatellite markers are expected to become useful tools to determine the population structure and conservation of E. oleifera populations.
    Matched MeSH terms: Microsatellite Repeats
  14. Characterisation of simple sequence repeats in the Asian seabass, Lates Calcarifer by random sequencing
    Wan KL, Chong PP, Adura Mohd. Adnan
    Sains Malaysiana, 2011;40.
    In recent years, there has been considerable interest in simple sequence repeats (SSRs) particularly as molecular markers with applications in many different fields. We have carried out an effort to identify and analyse SSRs in the genome of the Asian seabass, Lates calcarifer by random sequencing. Genomic DNA was isolated from the muscle tissue of L. calcarifer, sheared by nebulisation and ligated into plasmid vector. Recombinant clones were selected randomly from the genomic libraries constructed. Subsequently, plasmid DNA was extracted and subjected to one-pass sequencing. A total of 4175 random sequences, also known as genome survey sequences (GSSs), with a total length of 1.7 Mb was generated. Screening of the whole L. calcarifer GSS data set allowed for the identification of a total of 151 perfect (100% similarity) SSRs. These SSR consensus patterns spread over a wide range of size (1 to 226 bp). The most frequent consensus pattern is dinucleotide, which represents 60% of all SSRs identified. The dinucleotides (AC)n, (AT)n and (AG)n were also found to occur frequently in the L. calcarifer genome. Sequence comparison between L. calcarifer and other fish species showed variation in repeat content, indicating the different ways in which repeats may evolve in the genome of these species. Data generated from this random sequencing of the L. calcarifer genome should serve as a valuable resource for further studies of this organism.
    Matched MeSH terms: Microsatellite Repeats
  15. Population Genetic Structure and Breeding Pattern of Cimex hemipterus (F.) (Hemiptera: Cimicidae) in Malaysia
    Seri Masran SNA, Ab Majid AH
    J Med Entomol, 2019 06 27;56(4):942-952.
    PMID: 30882146 DOI: 10.1093/jme/tjz024
    The surge in tropical bed bug Cimex hemipterus (Fabricius) (Hemiptera: Cimicidae) infestations has led to an increase in genomic studies. In this study, the population genetics and breeding patterns of 22 Malaysian populations were analyzed, including genetic differentiation and genetic distance. For seven microsatellite loci, the number of alleles varied from 6 to 14. The allelels per loci contrasted sharply between the overall population and within the populations. The average observed and expected heterozygosity was 0.280 and 0.828 for the overall population and 0.281 and 0.657 among the populations, respectively. Based on polymorphic information criteria, the markers with a value >0.5 were highly polymorphic. In the Hardy-Weinberg equilibrium, the loci of Ch 09ttn, Ch 01dn, and Ch 13dn of the overall population showed signs of a null allele. The stutter peaks caused no scoring errors; large allele dropouts were not detected for any loci; and a correlation imbalance was not indicated. The genetic differentiation among populations was moderate, with a coefficient of genetic differentiation (FST) of 0.144. The bed bug populations showed strong inbreeding, with highly positive coefficients of inbreeding (FIS). The molecular variation attributed to inbreeding was 83% within the populations, compared with 17% among the populations. The admixture individuals in STRUCTURE and neighbor-joining phylogenetic trees also indicated weak genetic structure in the geographical populations, suggesting moderate gene flows between populations. Thus, moderately active dispersion and human-mediated transport shaped the genetic structure of C. hemipterus populations in Malaysia.
    Matched MeSH terms: Microsatellite Repeats
  16. Evaluation of genetic diversity of Clinacanthus nutans (Acanthaceaea) using RAPD, ISSR and RAMP markers
    Ismail NZ, Arsad H, Samian MR, Ab Majid AH, Hamdan MR
    Physiol Mol Biol Plants, 2016 Oct;22(4):523-534.
    PMID: 27924125
    Three polymerase chain reaction (PCR) techniques were compared to analyse the genetic diversity of Clinacanthus nutans eight populations in the northern region of Peninsular Malaysia. The PCR techniques were random amplified polymorphic deoxyribonucleic acids (RAPD), inter-simple sequence repeats (ISSR) and random amplified microsatellite polymorphisms (RAMP). Leaf genomic DNA was PCR amplified using 17 RAPD, 8 ISSR and 136 RAMP primers . However, only 10 RAPD primers, 5 ISSR primers and 37 RAMP primers produced reproducible bands. The results were evaluated for polymorphic information content (PIC), marker index (MI) and resolving power (RP). The RAMP marker was the most useful marker compared to RAPD and ISSR markers because it showed the highest average value of PIC (0.25), MI (11.36) and RP (2.86). The genetic diversity showed a high percentage of polymorphism at the species level compared to the population level. Furthermore, analysis of molecular variance revealed that the genetic diversity was higher within populations, as compared to among populations of C. nutans. From the results, the RAMP technique was recommended for the analysis of genetic diversity of C. nutans.
    Matched MeSH terms: Microsatellite Repeats
  17. Fulltext Chloroplast Genome Analysis for Genetic Information and Authentication in Five Barleria Species
    Kaewdaungdee S, Sudmoon R, Tanee T, Lee SY, Chaveerach A
    Genes (Basel), 2022 Sep 22;13(10).
    PMID: 36292590 DOI: 10.3390/genes13101705
    In order to authenticate the genomic information of Barleriacristata L., B. lupulina Lindl., B. repens Nees, B. siamensis Craib, and B. strigosa Willd, cp genomes were investigated. They revealed a general structure with a total size of 151,997-152,324 bp. The genomes encoded a total of 131 genes, including 86 CDS, 37 tRNA, and 8 rRNA genes. Other details found were as follows: different numbers and types of SSRs; identical gene content, which is adjacent to the border regions, except for B. strigosa, that revealed a shorter ndhF gene sequence and lacked the ycf1 gene; slightly different genetic distance values, which can be used for species identification; three distinct gaps of nucleotide variations between the species located at the intergenic spacer regions of the LSC and CDS of the SSC; three effective molecular markers derived from divergent hotspot regions, including the ccsA-ndhD, ndhA-ndhH-rps15, and ycf1. The genetic relationships derived from the cp genome and the CDS phylogenetic trees of Barleria and the 13 genera in Acanthaceae and different families, Scrophulariaceae and Phrymaceae, showed similar results. The six Barleria species as monophyletic groups with inner and outer outgroups were found to have perfect discrimination. These results have helped to authenticate the five Barleria species and the six genera in Acanthaceae.
    Matched MeSH terms: Microsatellite Repeats
  18. Integrated consensus genetic map and genomic scaffold re-ordering of oil palm (Elaeis guineensis) genome
    Mohd Sanusi NSN, Rosli R, Chan KL, Halim MAA, Ting NC, Singh R, et al.
    Comput Biol Chem, 2023 Feb;102:107801.
    PMID: 36528019 DOI: 10.1016/j.compbiolchem.2022.107801
    A high-quality reference genome is an important resource that can help decipher the genetic basis of traits in combination with linkage or association analyses. The publicly available oil palm draft genome sequence of AVROS pisifera (EG5) accounts for 1.535 Gb of the 1.8 Gb oil palm genome. However, the assemblies are fragmented, and the earlier assembly only had 43% of the sequences placed on pseudo-chromosomes. By integrating a number of SNP and SSR-based genetic maps, a consensus map (AM_EG5.1), comprising of 828.243 Mb genomic scaffolds anchored to 16 pseudo-chromosomes, was generated. This accounted for 54% of the genome assembly, which is a significant improvement to the original assembly. The total length of N50 scaffolds anchored to the pseudo-chromosomes increased by ∼18% compared to the previous assembly. A total of 139 quantitative trait loci for agronomically important quantitative traits, sourced from literature, were successfully mapped on the new pseudo-chromosomes. The improved assembly could also be used as a reference to identify potential errors in placement of specific markers in the linkage groups of the genetic maps used to assemble the consensus map. The 3422 unique markers from five genetic maps, anchored to the pseudo-chromosomes of AM_EG5.1, are an important resource that can be used preferentially to either construct new maps or fill gaps in existing genetic maps. Synteny analysis further revealed that the AM_EG5.1 had high collinearity with the date palm genome cultivar 'Barhee BC4' and shared most of its segmental duplications. This improved chromosomal-level genome is a valuable resource for genetic research in oil palm.
    Matched MeSH terms: Microsatellite Repeats
  19. Fulltext High density SNP and SSR-based genetic maps of two independent oil palm hybrids
    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: Microsatellite Repeats/genetics*
  20. Fulltext A review of microsatellite markers and their applications in rice breeding programs to improve blast disease resistance
    Miah G, Rafii MY, Ismail MR, Puteh AB, Rahim HA, Islam KhN, et al.
    Int J Mol Sci, 2013;14(11):22499-528.
    PMID: 24240810 DOI: 10.3390/ijms141122499
    Over the last few decades, the use of molecular markers has played an increasing role in rice breeding and genetics. Of the different types of molecular markers, microsatellites have been utilized most extensively, because they can be readily amplified by PCR and the large amount of allelic variation at each locus. Microsatellites are also known as simple sequence repeats (SSR), and they are typically composed of 1-6 nucleotide repeats. These markers are abundant, distributed throughout the genome and are highly polymorphic compared with other genetic markers, as well as being species-specific and co-dominant. For these reasons, they have become increasingly important genetic markers in rice breeding programs. The evolution of new biotypes of pests and diseases as well as the pressures of climate change pose serious challenges to rice breeders, who would like to increase rice production by introducing resistance to multiple biotic and abiotic stresses. Recent advances in rice genomics have now made it possible to identify and map a number of genes through linkage to existing DNA markers. Among the more noteworthy examples of genes that have been tightly linked to molecular markers in rice are those that confer resistance or tolerance to blast. Therefore, in combination with conventional breeding approaches, marker-assisted selection (MAS) can be used to monitor the presence or lack of these genes in breeding populations. For example, marker-assisted backcross breeding has been used to integrate important genes with significant biological effects into a number of commonly grown rice varieties. The use of cost-effective, finely mapped microsatellite markers and MAS strategies should provide opportunities for breeders to develop high-yield, blast resistance rice cultivars. The aim of this review is to summarize the current knowledge concerning the linkage of microsatellite markers to rice blast resistance genes, as well as to explore the use of MAS in rice breeding programs aimed at improving blast resistance in this species. We also discuss the various advantages, disadvantages and uses of microsatellite markers relative to other molecular marker types.
    Matched MeSH terms: Microsatellite Repeats/genetics*
Related Terms
Filters
Contact Us

Please provide feedback to Administrator ([email protected])

External Links