Biology subjects

Zhang, R. J.

Publications and source records attributed to Zhang, R. J..

5 recordsLinked to original sources

bioRxiv2026

Broad-spectrum in situ genetic reprogramming of native microbiomes

Complex microbial communities are found throughout terrestrial, aquatic, and animal-associated ecosystems. Genetic modification of discrete microbial taxa within native communities represents a powerful tool to study and augment microbiome functions. Herein, we develop Synthetic Phage Assisted Reprogrammable and Targetable Addition (SPARTA) as a one-step strategy for packaging, delivering, and integrating large synthetic DNA into a broad range of native microbiomes. SPARTA leverages a broad-spectrum synthetic phage particle for in situ genome engineering within complex soil, freshwater, and mammalian fecal microbiomes, reprogramming 59 native species across 16 families. By modulating SPARTA components, we further demonstrated tunability of SPARTA towards targeted microbiome population. Additionally, we built a novel companion tool to quantitatively identify engineered taxa, named 16S crRNA-guided inference of bacterial engineering sequencing or ScRibe-seq. The SPARTA-ScRibe-seq pipeline delivered and validated functional synthetic gene clusters in diverse native microbiomes while preserving the original microbial community structure. Together, this novel genome engineering framework constitutes an end-to-end programmable platform for rational and customizable reprogramming of native microbiomes.

bioengineering↗

bioRxiv2026

Creation of genomic chimeras via megabase scale genome expansion

An organism's physiology is controlled by its genomic content. Building genomic chimeras would enable melding of the diverse functions and properties of life. However, prior arts in genome synthesis are limited to reconstituting pre-existing functions within a singular genome rather than combining diverse genomic functions across multiple distinct genomes. Existing methods are also prohibitively expensive, labor intensive, and time consuming, and thus fundamentally not scalable for creating large synthetic chimeric genomes. To address all these limitations, we invented Additive Conjugative-CAST Engineering (ACE) combining conjugation with CRISPR-associated transposition (CAST) to deliver and integrate up to half a genome per step from a donor cell into a precisely defined position in the recipient's genome. We have demonstrated ACE's capability to integrate at least a 2-megabase donor genomic segment in a single step and at least 3 megabase in two consecutive steps. Importantly, we confirmed ACE's generality through the creation of multiple genomic chimeras across species, genus, and at least order barriers. With ACE, we further demonstrate such chimeric organisms, or what we call genome expanded organisms (GEOs), can be stably forged from at least three starting bacterial strains, and can be stably maintained to express all their acquired genomic parts in a single chimera. ACE offers a new paradigm of creating artificial lifeforms to combine desired properties and potentially create novel functions beyond the constraints of nature. ACE also offers a unique perspective to probe unexplored plasticity in genome architecture and expression patterns of novel, massively expanded genomes.

synthetic biology↗

bioRxiv2026

Rapid in vitro synthesis of DNA templates via Sidewinder for polyadenylated Hantavirus mRNA vaccine candidates

As the recent COVID-19 pandemic illustrated, zoonotic viruses and other pathogens pose a credible threat to public health. Recent advancements in vaccine technology, particularly mRNA vaccines, provide key tools for an effective and swift public health response. Although mRNA vaccines can be developed more quickly than traditional vaccines, fast and accurate construction of DNA templates for these vaccines remains a critical bottleneck. Using our novel DNA assembly technology, Sidewinder, we rapidly designed and built multiple mRNA vaccine candidates to guard against a potential outbreak of Hantavirus (ANDV). We successfully constructed the DNA templates from oligo pools and produced the mRNA for three vaccine candidates in just 2 days after delivery of the synthetic DNA oligos.

biochemistry↗

bioRxiv2025

Ultrasound imaging of in situ transcriptional activity in opaque tissue

Ultrasound imaging and acoustic reporter genes provide unique capabilities for in vivo biological imaging by leveraging ultrasounds ability to visualize opaque tissues with high spatiotemporal resolution. But until now, the expression of acoustic reporter genes - based on gas vesicle (GV) proteins - has been limited to ex vivo-modified cells due to the complexity of the GV gene cluster, precluding valuable in situ applications. Here, we develop a system capable of introducing GV genes directly into native tissues via stoichiometric multi-AAV delivery. We validate this system in the mouse brain, demonstrating well-tolerated in situ gene expression and repeated ultrasound imaging over more than a month in the same animal. Furthermore, by placing GV genes under the control of immediate early gene promoters, we demonstrate the ability to track in vivo gene expression changes arising from elevated neural activity during epileptic seizures. This work connects ultrasound to in situ transcriptional dynamics happening inside the opaque tissues of living creatures.

bioengineering↗

bioRxiv2022

A universal system for streamlined genome integrations with CRISPR-associated transposases

Genome engineering tools in bacteria are limited by their targeting abilities, cargo size capacities, and integration efficiencies. Programmable Cas-directed transposons have been shown to bypass these constraints; however, genome integrations with these Cas-directed transposons require a cargo plasmid carrying the desired DNA payload flanked by directed repeat transposon arms. This cloning pre-requisite significantly hinders the modularity and streamlining capabilities of Cas-directed transposon systems, diminishing their utility for genome engineering. Here, we present a system that can robustly integrate a linear DNA payload into the genome of E. coli by employing a Type I-F CRISPR-associated transposon from Vibrio cholerae. This system bypasses the traditional limiting factors of Cas-directed transposons by leveraging oligonucleotide design and nested polymerase chain reactions to reconstitute the transposon arms onto a designated cargo. Our findings demonstrate that this programmable linear integration method has high efficiencies in integrating large DNA payloads across multiple genomic loci.

synthetic biology↗