Biology subjects

Duryea, J.

Publications and source records attributed to Duryea, 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↗

bioRxiv2024

Mapping histological and functional maturation of human endocrine pancreas across early postnatal periods

Human endocrine cell differentiation and islet morphogenesis play critical roles in determining islet cell mass and function, but the events and timeline of these processes are incompletely defined. To better understand early human islet cell development and maturation, we collected 115 pediatric pancreata and mapped morphological and spatiotemporal changes from birth through the first ten years of life. Using quantitative analyses and a combination of complementary tissue imaging approaches, including confocal microscopy and whole-slide imaging, we developed an integrated model for endocrine cell formation and islet architecture, including endocrine cell type heterogeneity and abundance, endocrine cell proliferation, and islet vascularization and innervation. We also assessed insulin and glucagon secretory profiles in isolated islet preparations from pediatric donors aged 2 months to 10 years and found a temporal difference in the maturation of insulin secretion compared to glucagon secretion. This comprehensive summary of postnatal and pediatric pancreatic islet development provides a framework for future studies and integration of emerging genetic and genomic data related to islet biology and diabetes risk.

developmental biology↗

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

En1 and Lmx1b do not recapitulate embryonic dorsal-ventral limb patterning functions during mouse digit tip regeneration

The mouse digit tip is a complex tissue that is capable of regeneration after amputation. How the regenerated digit tip is patterned is unknown, but a long-standing hypothesis in the field of regeneration proposes that developmental patterning mechanisms are re-used during regeneration. The digit tip bone exhibits strong dorsal-ventral (DV) polarity, so we focus on Engrailed 1 (En1) and LIM homeobox transcription factor 1B (Lmx1b), two well-studied transcription factors necessary for DV patterning during limb development. We investigate if En1 and Lmx1b are re-expressed during regeneration in a developmental-like spatially restricted pattern, and if they direct DV morphology of the regenerated digit tip. We find that both En1 and Lmx1b are expressed in the regenerating mouse digit tip epithelium and mesenchyme, respectively, but without DV polarity. We use conditional genetics and quantitative analysis of digit tip bone morphology to determine that genetic deletion of En1 or Lmx1b in adult digit tip regeneration modestly reduces bone regeneration but does not affect DV patterning of the regenerate. Collectively, our data suggest that while En1 and Lmx1b are re-expressed during mouse digit tip regeneration, they do not define the DV axis during regeneration.

developmental biology↗

bioRxiv2021

Improving Lab Culture Through Self-Assessment: A Case Study

PurposeMotivated by perceived dissatisfaction within our labs changed working environment brought about by the COVID-19 pandemic, we performed a self-assessment of our lab culture through anonymous surveys and live sessions. MethodsIn Survey 1, we asked each lab member to identify and rank up to 10 values that are important for a healthy lab environment. They were then asked to rate how well the lab embodied those values at two time points: before the COVID-19 pandemic while working onsite, and at the time of the survey while working remotely (10 months into the pandemic). In a series of live group sessions, we reviewed relevant literature and the survey results to finalize ten themes. We then reflected on each theme and proposed action items to address any deficiencies. Finally, we conducted Survey 2 after the self-assessment to judge the groups finalized themes, implemented changes, and overall satisfaction with the assessment process. ResultsThemes identified were attitude, accountability, teamwork/collaboration, communication, diversity/inclusion, emotional intelligence, integrity, training, well-being, and adaptability in crisis-management. All lab members liked the self-assessment process and felt their voices were heard. On average, there was a 12% increase in satisfaction across all themes from the start to end of the lab assessment. ConclusionWe successfully assessed the culture of our lab and subsequently improved lab member satisfaction. The success of this team project suggests that other scientific labs could benefit from similar interactive self-assessments.

scientific communication and education↗

bioRxiv2017

The Generalized Data Model for Clinical Research

1.1.1 BackgroundMost healthcare data sources store information within their own unique schemas, making reliable and reproducible research challenging. Consequently, researchers have adopted various data models to improve the efficiency of research. Transforming and loading data into these models is a labor-intensive process that can alter the semantics of the original data. Therefore, we created a data model with a hierarchical structure that simplifies the transformation process and minimizes data alteration.\n\n1.2 MethodsThere were two design goals in constructing the tables and table relationships for the Generalized Data Model (GDM). The first was to focus on clinical codes in their original vocabularies to retain the original semantic representation of the data. The second was to retain hierarchical information present in the original data while retaining provenance. The model was tested by transforming synthetic Medicare data; Surveillance, Epidemiology, and End Results data linked to Medicare claims; and electronic health records from the Clinical Practice Research Datalink. We also tested a subsequent transformation from the GDM into the Sentinel data model.\n\n1.3 ResultsThe resulting data model contains 19 tables, with the Clinical Codes, Contexts, and Collections tables serving as the core of the model, and containing most of the clinical, provenance, and hierarchical information. In addition, a Mapping table allows users to apply an arbitrarily complex set of relationships among vocabulary elements to facilitate automated analyses.\n\n1.4 ConclusionsThe GDM offers researchers a simpler process for transforming data, clear data provenance, and a path for users to transform their data into other data models. The GDM is designed to retain hierarchical relationships among data elements as well as the original semantic representation of the data, ensuring consistency in protocol implementation as part of a complete data pipeline for researchers.

bioinformatics↗