Biology subjects

Snow, K. J.

Publications and source records attributed to Snow, K. J..

6 recordsLinked to original sources

bioRxiv2026

Novel mouse reporter models for the detection of genome editing events in vivo

With the expansion of therapeutic gene editing technology, small animal models provide essential platforms to evaluate the function of these new approaches in vivo. As part of the Somatic Cell Genome Editing (SCGE) Consortium, we developed next-generation murine reporters that overcome current model limitations and broaden detectable in vivo editing outcomes. These include two mouse models built on the "traffic light" reporter concept. This system enables fluorescent detection of both gene repair (green) and CRISPR-generated indels (red) events following editing by a single guide and either dsDNA or single-stranded oligonucleotide donor. We also generated a third reporter model that efficiently detects A-base editor activity. Reporters were validated in cultured embryos, via germline editing, and through activation in vivo by AAV transduction or direct ribonucleoprotein delivery. Together, these new models provide a valuable resource for improved detection of genome editing events in vivo.

genomics↗

bioRxiv2026

Modeling patient variants of Cnot1 and Cdc42bpb results in distinct forms of congenital diaphragmatic hernia in mice

Congenital diaphragmatic hernia (CDH) is a severe congenital anomaly characterized by impairment of both diaphragm and lung development in utero. CDH presents as a spectrum of forms and severities, with diaphragm defects arising in the dorsal/posterior region typically correlating with more severe pulmonary disease and higher risk of mortality than those appearing in ventral/anterior regions. The genetic etiology underlying CDH is complex, with many genes implicated showing variable expressivity and incomplete penetrance in both human patients and mouse models. Here we present in vivo validation of two genes previously unassociated with CDH: the CDC42-interacting kinase CDC42BPB; and CNOT1, a scaffolding protein of the CCR4-NOT protein complex, critical for mRNA regulation through modifications such as deadenylation. Each gene was found to have a damaging, de novo missense variant in a recent large-scale CDH patient sequencing screen. Loss of Cdc42bpb leads to ventral diaphragmatic hernias, heart septal defects and minor lung epithelial differentiation defects in mouse embryos. Installation of the orthologous patient-specific missense variant through CRISPR/Cas9 editing leads to less severe ventral diaphragm defects. Mouse embryos with either one or two copies of the orthologous Cnot1 variant, c.1867C>T (p.R623W), develop dorsal diaphragmatic hernias with low (<50%) penetrance, and mutants showed alterations in mRNA isoform expression consistent with the molecular role of Cnot1 in RNA splicing. These results underscore the power of in vivo functional modeling to validate genes and patient-specific variants uncovered by patient sequencing, reveal two previously unrecognized genetic causes of CDH, and highlight the heterogeneity of different patient anatomic presentations.

genetics↗

bioRxiv2025

Efficient in vivo mammalian neuron editing using peptide-mediated CRISPR enzyme delivery

CRISPR-mediated genome editing of the central nervous system (CNS) has the potential to revolutionize the treatment of neurological disorders, including neurodegenerative disorders such as Huntingtons disease (HD). However, the development of CRISPR therapeutics for the CNS has been hindered by challenges associated with delivery, specifically the lack of a clinically compatible, non-viral delivery technology facilitating genome editing of neurons in vivo. For most indications, two key obstacles must be overcome before therapeutic genome editing of the brain is feasible: non-toxic intracellular delivery of CRISPR cargo into neurons and establishment of strategies enabling targeted brain regions to be edited efficiently. While viral vectors have shown promise in pre-clinical models, non-viral approaches present distinct advantages: ease of manufacture as well as the transient presence of CRISPR machinery, which tempers risks of genotoxicity and immunogenicity. Peptide-enabled ribonucleoprotein (RNP) delivery of CRISPR (PERC) has emerged as a promising non-viral delivery strategy for CRISPR enzymes with initial use in primary human immune cells. In this study, we report the development of Neuro-PERC, a streamlined and optimized approach for in vivo editing of mammalian neurons. Administration of Neuro-PERC reagents via convection-enhanced delivery (CED) mediated efficient and well-tolerated neuronal genome editing. Neuro-PERC enabled robust neuronal editing in the brain of both small and large animal reporter models, and increased survival in a severe murine model of Huntingtons disease. These results establish CED-administered Neuro-PERC as a candidate delivery technology to hasten clinical translation of CRISPR-based therapies for diseases of the CNS. SummaryNeuro-PERC, a peptide-mediated CRISPR enzyme delivery technology, enables efficient in vivo mammalian neuronal editing in the brain of mice and pigs, extending survival in a murine model of Huntingtons disease when administered via convection-enhanced delivery (CED).

neuroscience↗

bioRxiv2024

A Comprehensive Atlas of AAV Tropism in the Mouse

Gene therapy with Adeno-Associated Viral (AAV) vectors requires knowledge of their tropism within the body. Here we analyze the tropism of ten naturally occurring AAV serotypes (AAV3B, AAV4, AAV5, AAV6, AAV7, AAV8, AAV9, AAVrh8, AAVrh10 and AAVrh74) following systemic delivery into male and female mice. A transgene expressing ZsGreen and Cre recombinase was used to identify transduction in a cell-dependent manner based on fluorescence. Cre-driven activation of tdTomato fluorescence offered superior sensitivity for transduced cells. All serotypes except AAV3B and AAV4 had high liver tropism. Fluorescence activation revealed transduction of unexpected tissues, including adrenals, testes and ovaries. Rare transduced cells within tissues were also readily visualized. Biodistribution of AAV genomes correlated with fluorescence, except in immune tissues. AAV4 was found to have a pan-endothelial tropism while also targeting pancreatic beta cells. This public resource enables selection of the best AAV serotypes for basic science and preclinical applications in mice.

molecular biology↗

bioRxiv2022

Focused ultrasound-mediated brain genome editing

Gene editing in the mammalian brain has been challenging because of the restricted transport imposed by the blood-brain barrier (BBB). Current approaches rely on local injection to bypass the BBB. However, such administration is highly invasive and not amenable to treating certain delicate regions of the brain. We demonstrate a safe and effective gene editing technique by using focused ultrasound (FUS) to transiently open the BBB for the transport of intravenously delivered CRISPR/Cas9 machinery to the brain.

bioengineering↗

bioRxiv2022

Efficient in vivo neuronal genome editing in the mouse brain using nanocapsules containing CRISPR-Cas9 ribonucleoproteins

Genome editing of somatic cells via clustered regularly interspaced short palindromic repeats (CRISPR) offers promise for new therapeutics to treat a variety of genetic disorders, including neurological diseases. However, the dense and complex parenchyma of the brain and the post-mitotic state of neurons make efficient genome editing challenging. In vivo delivery systems for CRISPR-Cas proteins and single guide RNA (sgRNA) include both viral vectors and non-viral strategies, each presenting different advantages and disadvantages for clinical application. We developed non-viral and biodegradable PEGylated nanocapsules (NCs) that deliver preassembled Cas9-sgRNA ribonucleoproteins (RNPs). Here, we show that the RNP NCs led to robust genome editing in neurons following intracerebral injection into the mouse striatum. Genome editing was predominantly observed in medium spiny neurons (>80%), with occasional editing in cholinergic, calretinin, and parvalbumin interneurons. Glial activation was minimal and was localized along the needle tract. Our results demonstrate that the RNP NCs are capable of safe and efficient neuronal genome editing in vivo. SIGNIFICANCE STATEMENTModifying the DNA of cells in the brain could present opportunities for new treatments of neurological diseases. In this report, we describe a nanocapsule system designed to deliver the elements needed to modify the DNA of brain cells, also known as genome editing. These nanocapsules are created by chemically encapsulating the genome editing components, such that the nanocapsules are stable when prepared and biodegradable to release their payload upon entering cells. When injected into the mouse brain, our research shows that the nanocapsules lead to safe and efficient editing of DNA in neurons.

neuroscience↗