Publications by authors named "Yii Leng Chua"

Background: A new nucleic acid-based assay (simple amplification-based assay [SAMBA]) for rapid visual detection of human immunodeficiency virus-type 1 (HIV-1) by dipstick is described. The assay was designed to be simple, stable, robust, self-contained, and capable of detecting a broad spectrum of HIV-1 subtypes and recombinant forms.

Methods: The performance of the SAMBA HIV-1 test (amplification and detection chemistry) was evaluated using the World Health Organization HIV-1 RNA Genotype Reference Panel, with clinical samples representing various viral subtypes and recombinant forms common in sub-Saharan Africa.

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The transition from the juvenile to the mature phase during vegetative development in plants is characterized by changes in leaf shape. We show that GENERAL TRANSCRIPTION FACTOR GROUP E6 (GTE6) regulates differences in leaf patterning between juvenile and mature leaves in Arabidopsis. GTE6 encodes a novel small bromodomain-containing protein unique to plants.

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The acetylation states of histones present on the upstream, promoter, coding or intronic regions of 88 tobacco genes were examined with chromatin immunoprecipitation (ChIP) experiments using antibodies that recognised acetylated histone H4. The DNA sequences enriched in the immunoprecipitates were amplified by ligation-mediated PCR, labelled with Cy-dUTP and hybridised to DNA microarrays. In green tobacco shoots, histone H4 acetylation was localised to 300-600-bp sequences in the promoters or coding regions of 31 genes, or occurred extensively over several kilobase-pair regions containing the upstream, promoter and/or coding regions of 25 genes.

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The influence of the transcriptional enhancer of the pea plastocyanin gene (PetE) on the acetylation of histones was examined with chromatin immunoprecipitation (ChIP) experiments using antibodies that recognize acetylated or nonacetylated histones H3 and H4. In transgenic tobacco plants containing the pea PetE promoter fused to uidA, both acetylated and nonacetylated histones H3 and H4 were present on the integrated transgene. Linking the PetE enhancer to the transgene resulted in increased beta-glucuronidase activity and increased amounts of acetylated histones H3 and H4 present on the promoter, suggesting that the enhancer may increase transcription by mediating the acetylation of histones.

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