Publications by authors named "Cheljong Hong"

Prime editing is widely used in many organisms to introduce site-specific sequence modifications, such as base substitutions, insertions, and deletions, in genomic DNA without generating double-strand breaks. Despite their wide-ranging applications, prime editors (PEs) have low editing efficiency, especially in dicot plants, and are therefore barely used for genome engineering in these plant species. Here, based on the previous approaches used to improve prime editing efficiency, we generated multiple different combinations of PE components and prime editing guide RNAs (pegRNAs) and examined their prime editing efficiency in Arabidopsis thaliana protoplasts as the dicot model system.

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Chromatin configuration is critical for establishing tissue identity and changes substantially during tissue identity transitions. The crucial scientific and agricultural technology of in vitro tissue culture exploits callus formation from diverse tissue explants and tissue regeneration via de novo organogenesis. We investigated the dynamic changes in H3ac and H3K4me3 histone modifications during leaf-to-callus transition in Arabidopsis thaliana.

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Prime editors (PEs), which are CRISPR-Cas9 nickase (H840A)-reverse transcriptase fusion proteins programmed with prime editing guide RNAs (pegRNAs), can not only edit bases but also install transversions, insertions, or deletions without both donor DNA and double-strand breaks at the target DNA. As the demand for in-locus tagging is increasing, to reflect gene expression dynamics influenced by endogenous genomic contexts, we demonstrated that PEs can be used to introduce the hemagglutinin (HA) epitope tag to a target gene locus, enabling molecular and biochemical studies using in-locus tagged plants. To promote genome-wide in-locus tagging, we also implemented a publicly available database that designs pegRNAs for in-locus tagging of all the Arabidopsis genes.

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The circadian clock synchronizes endogenous rhythmic processes with environmental cycles and maximizes plant fitness. Multiple regulatory layers shape circadian oscillation, and chromatin modification is emerging as an important scheme for precise circadian waveforms. Here, we report the role of an evolutionarily conserved Sin3-histone deacetylase complex (HDAC) in circadian oscillation in .

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