Biology subjects

Wu, C.-t.

Publications and source records attributed to Wu, C.-t..

4 recordsLinked to original sources

bioRxiv2024

Cryosectioning-enabled super-resolution microscopy for studying nuclear architecture at the single protein level

DNA-PAINT enables nanoscale imaging with virtually unlimited multiplexing and molecular counting. Here, we address challenges, such as variable imaging performance and target accessibility, that can limit its broader applicability. Specifically, we enhance its capacity for robust single-protein imaging and molecular counting by optimizing the integration of TIRF microscopy with physical sectioning, in particular, Tokuyasu cryosectioning. Our method, tomographic & kinetically enhanced DNA-PAINT (tkPAINT), achieves 3 nm localization precision across diverse samples, enhanced imager binding, and improved cellular integrity. tkPAINT can facilitate molecular counting with DNA-PAINT inside the nucleus, as demonstrated through its quantification of the in situ abundance of RNA Polymerase II in both HeLa cells as well as mouse tissues. Anticipating that tkPAINT could become a versatile tool for the exploration of biomolecular organization and interactions across cells and tissues, we also demonstrate its capacity to support multiplexing, multimodal targeting of proteins and nucleic acids, and 3D imaging.

cell biology↗

bioRxiv2022

Quantitative multiplexed imaging of chromatin ultrastructure with Decode-PAINT

Super-resolution chromatin imaging techniques are emerging as powerful tools for spatial genomics. However, it remains challenging to visualize the genome on the order of tens of nanometers, a scale that can reveal rich structural detail about the nuclear organization. Here we introduce Decode-PAINT, a multiplexed in situ method, which leverages rapid diffraction-limited pre-decoding and DNA-PAINT (DNA points accumulation for imaging nanoscale topography). Decode-PAINT visualizes multiple discrete genomic regions at a resolution close to the nucleosome scale with a simple and easy-to-implement optical setup, reduces total imaging time by omitting multiple rounds of single-molecule recording, and enables the interrogation of the ultrastructure of the targets with <12 nm lateral and <20 nm axial resolution. We showcase the ability of our approach to perform multiplexed, high-resolution profiling of chromatin structure by performing targeted imaging of nine regions of active and inactive X chromosomes in individual cells. In short, Decode-PAINT accelerates in situ structural genomics.

systems biology↗

bioRxiv2018

The genome-wide, multi-layered architecture of chromosome pairing in early Drosophila embryos

Genome organization involves cis and trans chromosomal interactions, both implicated in gene regulation, development, and disease. Here, we focused on trans interactions in Drosophila, where homologous chromosomes are paired in somatic cells from embryogenesis through adulthood. We first addressed the long-standing question of whether pairing extends genome-wide and, to this end, developed a haplotype-resolved Hi-C approach that uses a new strategy to minimize homolog misassignment and thus robustly distinguish trans-homolog from cis contacts. This approach revealed striking genome-wide pairing in Drosophila embryos. Moreover, we discovered pairing to be surprisingly structured, with trans-homolog domains and interaction peaks, many coinciding with the positions of analogous cis features. We also found a significant correlation between pairing and the chromatin accessibility mediated by the pioneer factor Zelda. Our findings reveal a complex, highly structured organization underlying homolog pairing, first discovered more than a century ago.\n\nOne Sentence SummaryA robust approach for haplotype-resolved Hi-C reveals highly-structured homolog pairing in early stage Drosophila embryos.

genetics↗

bioRxiv2017

OligoMiner: A rapid, flexible environment for the design of genome-scale oligonucleotide in situ hybridization probes

Oligonucleotide (oligo)-based fluorescence in situ hybridization (FISH) has emerged as an important tool for the study of chromosome organization and gene expression and has been empowered by the commercial availability of highly complex pools of oligos. However, a dedicated bioinformatic design utility has yet to be created specifically for the purpose of identifying optimal oligo FISH probe sequences on the genome-wide scale. Here, we introduce OligoMiner, a rapid and robust computational pipeline for the genome-scale design of oligo FISH probes that affords the scientist exact control over the parameters of each probe. Our streamlined method uses standard bioinformatic file formats, allowing users to seamlessly integrate existing and new utilities into the pipeline as desired, and introduces a novel method for evaluating the specificity of each probe molecule that connects simulated hybridization energetics to rapidly generated sequence alignments using supervised learning. We demonstrate the scalability of our approach by performing genome-scale probe discovery in numerous model organism genomes and showcase the performance of the resulting probes with both diffraction-limited and single-molecule super-resolution imaging of chromosomal and RNA targets. We anticipate this pipeline will make the FISH probe design process much more accessible and will more broadly facilitate the design of pools of hybridization probes for a variety of applications.

bioinformatics↗