Selected Grantee Publications
The Effect of Common Paralytic Agents Used for Fluorescence Imaging on Redox Tone and ATP Levels in Caenorhabditis elegans
Morton et al., PLOS One. 2024.
https://pubmed.ncbi.nlm.nih.gov/38669260
Caenorhabditis elegans is a highly valuable model organism in biological research. However, these worms must be paralyzed for most imaging applications, and the effect that common chemical anesthetics may have on the parameters measured—especially biochemical measurements such as cellular energetics and redox tone—is poorly understood. In this study, the authors used two reporters—QUEEN-2m for relative ATP levels and reduction-oxidation–sensitive green fluorescent protein for redox tone—to assess the impact of commonly used chemical paralytics. The results show that all chemical anesthetics at doses required for full paralysis alter redox tone and/or ATP levels, and anesthetic use alters the detected outcome of rotenone exposure on relative ATP levels and redox tone. Therefore, it is important to tailor the use of anesthetics to different endpoints and experimental questions and to develop less disruptive paralytic methods for optimal imaging of dynamic in vivo reporters. Supported by ORIP (P40OD010440, R44OD024963) and NIEHS.
Disruption of Myelin Structure and Oligodendrocyte Maturation in a Macaque Model of Congenital Zika Infection
Tisoncik-Go et al., Nature Communications. 2024.
https://www.nature.com/articles/s41467-024-49524-2
Maternal infection during pregnancy can have severe consequences on fetal development and survival. Using a pigtail macaque model for Zika virus infection, researchers show that in utero exposure of a fetus to Zika virus due to maternal infection results in significantly decreased myelin formation around neurons. Myelin is a protective sheath that forms around neurons and is required for brain processing speed. This study suggests that reduced myelin resulting from Zika infection in utero is likely a contributing factor to severe deficits in brain development and microcephaly. Supported by ORIP (P51OD010425), NEI, and NIAID.
Genetic Diversity of 1,845 Rhesus Macaques Improves Genetic Variation Interpretation and Identifies Disease Models
Wang et al., Nature Communications. 2024.
https://www.nature.com/articles/s41467-024-49922-6
Nonhuman primates are ideal models for certain human diseases, including retinal and neurodevelopmental disorders. Using a reverse genetics approach, researchers profiled the genetic diversity of rhesus macaque populations across eight primate research centers in the United States and uncovered rhesus macaques carrying naturally occurring pathogenic mutations. They identified more than 47,000 single-nucleotide variants in 374 genes that had been previously linked with retinal and neurodevelopmental disorders in humans. These newly identified variants can be used to study human disease pathology and to test novel treatments. Supported by ORIP (P51OD011107, P51OD011106, P40OD012217, S10OD032189), NEI, NIAID, and NIMH.
Potent HPIV3-Neutralizing IGHV5-51 Antibodies Identified from Multiple Individuals Show L Chain and CDRH3 Promiscuity
Abu-Shmais et al., Journal of Immunology. 2024.
https://pubmed.ncbi.nlm.nih.gov/38488511/
Human parainfluenza virus 3 fusion glycoprotein (HPIV3 F), responsible for facilitating viral entry into host cells, is a major target of neutralizing antibodies that inhibit infection. More work is needed to understand these dynamics. Researchers characterized the genetic signatures, epitope specificity, neutralization potential, and publicness of HPIV3-specific antibodies identified across multiple individuals. From this work, they identified 12 potently neutralizing antibodies targeting three nonoverlapping epitopes on HPIV3 F. Six of the antibodies used immunoglobulin heavy variable gene, IGHV 5-51. These antibodies used different L chain variable genes (VL) and diverse H chain CDR 3 (CDRH3) sequences. These findings help elucidate the genetic and functional characteristics of HPIV3-neutralizing antibodies and indicate the existence of a reproducible H chain variable–dependent antibody response associated with VL and CDRH3 promiscuity. Supported by ORIP (K01OD036063), NCATS, NCI, NEI, NIAID, and NIDDK.
Disentangling the Link Between Zebrafish Diet, Gut Microbiome Succession, and Mycobacterium chelonae Infection
Sieler et al., Animal Microbiome. 2023.
https://pubmed.ncbi.nlm.nih.gov/37563644/
Despite the long-established importance of zebrafish (Danio rerio) as a model organism and their increasing use in microbiome-targeted studies, relatively little is known about how husbandry practices involving diet impact the zebrafish gut microbiome. Given the microbiome's important role in mediating host physiology and the potential for diet to drive variation in microbiome composition, the authors sought to clarify how three different dietary formulations that are commonly used in zebrafish facilities impact the gut microbiome. They report that diet drives the successional development of the gut microbiome, as well as its sensitivity to exogenous exposure. Consequently, investigators should carefully consider the role of diet in their microbiome zebrafish investigations, especially when integrating results across studies that vary by diet. Supported by ORIP (R24OD010998) and NIEHS.
De Novo Protein Fold Design Through Sequence-Independent Fragment Assembly Simulations
Pearce et al., PNAS. 2023.
https://doi.org/10.1073/pnas.2208275120
Researchers developed an automated open-source program, FoldDesign, to create high-fidelity stable folds. Through sequence-independent replica-exchange Monte Carlo simulations and energy force field optimalization of secondary structure, FoldDesign can render novel areas of protein structure and function space that natural proteins have not reached through evolution. These completely different yet stable structures replicate natural proteins’ characteristics with closely matching buried residues and solvent-exposed areas. This work demonstrates a strong potential of creating desired protein structures with potential clinical and industrial applications. Supported by ORIP (S10OD026825), NIAID, NCI, NIEHS, and NIGMS.
Gigapixel Imaging With a Novel Multi-Camera Array Microscope
Thomson et al., eLife. 2022.
https://www.doi.org/10.7554/eLife.74988
The dynamics of living organisms are organized across many spatial scales. The investigators created assembled a scalable multi-camera array microscope (MCAM) that enables comprehensive high-resolution, large field-of-view recording from multiple spatial scales simultaneously, ranging from structures that approach the cellular scale to large-group behavioral dynamics. By collecting data from up to 96 cameras, they computationally generated gigapixel-scale images and movies with a field of view over hundreds of square centimeters at an optical resolution of 18 µm. This system allows the team to observe the behavior and fine anatomical features of numerous freely moving model organisms on multiple spatial scales (e.g., larval zebrafish, fruit flies, slime mold). Overall, by removing the bottlenecks imposed by single-camera image acquisition systems, the MCAM provides a powerful platform for investigating detailed biological features and behavioral processes of small model organisms. Supported by ORIP (R44OD024879), NIEHS, NCI, and NIBIB.
Cell-Specific Regulation of Gene Expression Using Splicing-Dependent Frameshifting
Ling et al., Nature Communications. 2022.
https://www.doi.org/10.1038/s41467-022-33523-2
Precise and reliable cell-specific gene delivery remains technically challenging. Investigators report a splicing-based approach for controlling gene expression whereby separate translational reading frames are coupled to the inclusion or exclusion of mutated, frameshifting cell-specific alternative exons. Candidate exons are identified by analyzing thousands of publicly available RNA sequencing datasets and filtering by cell specificity, conservation, and local intron length. This method, which they denote as splicing-linked expression design (SLED), can be combined in a Boolean manner with such existing techniques as minipromoters and viral capsids. SLED can use strong constitutive promoters, without sacrificing precision, by decoupling the tradeoff between promoter strength and selectivity. AAV-packaged SLED vectors can selectively deliver fluorescent reporters and calcium indicators to various neuronal subtypes in vivo. The authors also demonstrate gene therapy utility by creating SLED vectors that can target PRPH2 and SF3B1 mutations. The flexibility of SLED technology enables creative avenues for basic and translational research. Supported by ORIP (T32OD011089, S10OD026859), NEI, and NIMH.
A Multidimensional Metabolomics Workflow to Image Biodistribution and Evaluate Pharmacodynamics in Adult Zebrafish
Jackstadt et al., Disease Models & Mechanisms. 2022.
https://www.doi.org/10.1242/dmm.049550
The evaluation of tissue distribution and pharmacodynamic properties of a drug is essential but often expensive in clinical research. The investigators developed a multidimensional metabolomics platform to evaluate drug activity that integrates mass spectrometry–based imaging, absolute drug quantitation, in vivo isotope tracing, and global metabolome analysis in zebrafish. They validated this platform by evaluating whole-body distribution of the anti-rheumatic agent hydroxychloroquine sulfate and its impact on the systemic metabolism of adult zebrafish. This work suggests that the multidimensional metabolomics platform is a cost-effective method for evaluating on- and off-target effects of drugs. Supported by ORIP (R24OD024624) and NIEHS.
Parallel Processing, Hierarchical Transformations, and Sensorimotor Associations along the “Where” Pathway
Doudlah et al., eLife. 2022.
https://www.doi.org/10.7554/eLife.78712
Visually guided behaviors require the brain to transform ambiguous retinal images into object-level spatial representations and map those representations to motor responses. These capabilities are supported by the dorsal “where” pathway in the brain, but the specific contributions of areas along this pathway have remained elusive. Using a rhesus macaque model, researchers compared neuronal activity in two areas along the “where” pathway that bridge the parieto-occipital junction: intermediate visual area V3A and the caudal intraparietal (CIP) area. Neuronal activity was recorded while the animals made perceptual decisions based on judging the tilt of 3D visual patterns. The investigators found that CIP shows higher-order spatial representations and more choice-correlated responses, which support a V3A-to-CIP hierarchy. The researchers also discovered modulation of V3A activity by extraretinal factors, suggesting that V3A might be better characterized as contributing to higher-order behavioral functions rather than low-level visual feature processing. Supported by ORIP (P51OD011106), NEI, NICHD, and NINDS.