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Biology subjects

Hung, P.-H.

Publications and source records attributed to Hung, P.-H..

3 recordsLinked to original sources

High-throughput DNA engineering by mating bacteria

To reduce the operational friction and scale DNA engineering, we report here an in vivo DNA assembly technology platform called SCRIVENER (Sequential Conjugation and Recombination for In Vivo Elongation of Nucleotides with low ERrors). SCRIVENER combines bacterial conjugation, in vivo DNA cutting, and in vivo homologous recombination to seamlessly stitch blocks of DNA together by mating E. coli in large arrays or pools. This workflow is simpler, cheaper, and higher throughput than current DNA assembly approaches that require DNA to be moved in and out of cells at different procedural steps. We perform over 5,000 assemblies with two to 13 DNA blocks that range from 240 bp to 8 kb and show that SCRIVENER is capable of assembling constructs as long as 23 kb at relatively high throughput and fidelity. Most SCRIVENER errors are deletions between long interspersed repeats. However, SCRIVENER can overcome these errors by enabling assembly and sequence verification at high replication at a nominal additional cost per replicate. We show that SCRIVENER can be used to build combinatorial libraries in arrays or pools, and that DNA blocks onboarded into the platform can be repurposed and reused with any other DNA block in high throughput without a PCR step. Because of these features, DNA engineering with SCRIVENER has the potential to accelerate design-build-test-learn cycles of DNA products.

synthetic biology↗

Arrayed in vivo barcoding for multiplexed sequence verification of plasmid DNA and demultiplexing of pooled libraries

Sequence verification of plasmid DNA is critical for many cloning and molecular biology workflows. To leverage high-throughput sequencing, several methods have been developed that add a unique DNA barcode to individual samples prior to pooling and sequencing. However, these methods require an individual plasmid extraction and/or in vitro barcoding reaction for each sample processed, limiting throughput and adding cost. Here, we develop an arrayed in vivo plasmid barcoding platform that enables pooled plasmid extraction and library preparation for Oxford Nanopore sequencing. This method has a high accuracy and recovery rate, and greatly increases throughput and reduces cost relative to other plasmid barcoding methods or Sanger sequencing. We use in vivo barcoding to sequence verify >45,000 plasmids and show that the method can be used to transform error-containing dispersed plasmid pools into sequence-perfect arrays or well-balanced pools. In vivo barcoding does not require any specialized equipment beyond a low-overhead Oxford Nanopore sequencer, enabling most labs to flexibly process hundreds to thousands of plasmids in parallel.

synthetic biology↗

Differential Hsp90-dependent gene expression is strain-specific and common among yeast strains

Enhanced phenotypic diversity increases the likelihood of a population surviving catastrophic conditions. It has been suggested that Hsp90, an essential molecular chaperone in eukaryotes, can suppress (i.e., buffer) or enhance (i.e., potentiate) the effects of genetic variation, enabling organisms to adjust their levels of phenotypic diversity in response to environmental cues. Many Hsp90-interacting proteins are involved in signaling transduction pathways and transcriptional regulation. However, it remains unclear if Hsp90-dependent differential gene expression is common in natural populations. By examining the gene expression profiles of five diverse yeast strains, we identified many genes exhibiting Hsp90-dependent strain-specific differential expression. We employed an analysis pipeline to identify transcription factors (TFs) potentially contributing to variable expression. We found that upon Hsp90 inhibition or heat stress, activities or abundances of Hsp90-dependent TFs varied among strains, resulting in differential strain-specific expression of their target genes, which consequently led to phenotypic diversity. We provide evidence that individual populations can readily display specific Hsp90-dependent gene expression, suggesting that the evolutionary impacts of Hsp90 are widespread in nature. HighlightsO_LIHsp90-dependent gene expression varies among different yeast strains. C_LIO_LIHsp90 differentially influences transcriptional activity or protein abundances of transcription factors among yeast strains. C_LIO_LIDifferential strain-specific gene expression is correlated with phenotypic variations upon Hsp90 inhibition. C_LIO_LIHsp90-mediated strain-specific regulation manifests under environmental stress. C_LI

evolutionary biology↗