Selected Grantee Publications
A New Drosophila melanogaster Research Resource: CRISPR-Induced Mutations for Clonal Analysis of Fourth Chromosome Genes
Weasner et al., G3 (Bethesda). 2025.
https://pubmed.ncbi.nlm.nih.gov/39804955
The fruit fly, Drosophila melanogaster, shares approximately 60% of its genes with human homologs and is an excellent model organism for studying mechanisms underlying human health and disease. However, the fourth chromosome of this organism is challenging to study because of the lack of genetic resources. This study presents a new resource—the Fourth Chromosome Resource Project—for studying the fourth chromosome of the fruit fly and expanding the understanding of gene function and disease mechanisms. Using gene editing approaches, researchers generated and characterized 119 mutations in 62 fourth chromosome genes, including 84 predicted null alleles and 29 in-frame deletions. Phenotypic assessments included tests for lethality, sterility, and visible traits. Many stable mutant stocks were submitted into public repositories in the United States and Japan for research purposes. Supported by ORIP (P40OD018537, R24OD028242) and NHGRI.
Suppressing APOE4-Induced Neural Pathologies by Targeting the VHL-HIF Axis
Jiang et al., PNAS. 2025.
https://pubmed.ncbi.nlm.nih.gov/39874294
The ε4 variant of human apolipoprotein E (APOE4) is a major genetic risk factor for Alzheimer’s disease and increases mortality and neurodegeneration. Using Caenorhabditis elegans and male APOE-expressing mice, researchers determined that the Von Hippel-Lindau 1 (VHL-1) protein is a key modulator of APOE4-induced neural pathologies. This study demonstrated protective effects of the VHL-1 protein; the loss of this protein reduced APOE4-associated neuronal and behavioral damage by stabilizing hypoxia-inducible factor 1 (HIF-1), a transcription factor that protects against cellular stress and injury. Genetic VHL-1 inhibition also mitigated cerebral vascular injury and synaptic damage in APOE4-expressing mice. These findings suggest that targeting the VHL–HIF axis in nonproliferative tissues could reduce APOE4-driven mortality and neurodegeneration. Supported by ORIP (R24OD010943, R21OD032463, P40OD010440), NHGRI, NIA, and NIGMS.
Dysregulation of mTOR Signalling Is a Converging Mechanism in Lissencephaly
Zhang et al., Nature. 2025.
https://pubmed.ncbi.nlm.nih.gov/39743596
Lissencephaly (smooth brain) is a rare genetic condition, with such symptoms as epilepsy and intellectual disability and a median life expectancy of 10 years. This study reveals that reduced activity of the mTOR pathway may be a common cause of lissencephaly. Researchers used laboratory-grown brain models (organoids) and sequencing and spectrometry techniques to identify decreased mTOR activation in two types of lissencephaly disorders: p53-induced death domain protein 1 and Miller–Dieker lissencephaly syndrome. Pharmacological activation of mTOR signaling with a brain-selective mTORC1 activator molecule, NV-5138, prevented and reversed the morphological and functional defects in organoids. These findings suggest that mTOR dysregulation contributes to the development of lissencephaly spectrum disorders and highlight a potential druggable pathway for therapy. Supported by ORIP (S10OD018034, S10OD019967, S10OD030363), NCATS, NHGRI, NICHD, NIDA, NIGMS, NIMH, and NINDS.
Systematic Ocular Phenotyping of 8,707 Knockout Mouse Lines Identifies Genes Associated With Abnormal Corneal Phenotypes
Vo et al., BMC Genomics. 2025.
https://pubmed.ncbi.nlm.nih.gov/39833678
Corneal dysmorphologies (CDs) are a group of acquired but predominantly genetically inherited eye disorders that cause progressive vision loss and can be associated with systemic abnormalities. This study aimed to identify candidate CD genes in humans by looking at knockout mice with targeted deletions of orthologous genes that exhibited statistically significant corneal abnormalities. Analysis of data from 8,707 knockout mouse lines identified 213 candidate CD genes; 176 (83%) genes have not been implicated previously in CD. Bioinformatic analyses implicated candidate genes in several signaling pathways (e.g., integrin signaling pathway, cytoskeletal regulation by Rho GTPase, FAS signaling pathway), which are potential therapeutic targets. Supported by ORIP (U42OD011175, R03OD032622, UM1OD023221), NEI, and NHGRI.
A Revamped Rat Reference Genome Improves the Discovery of Genetic Diversity in Laboratory Rats
de Jong, Cell Genomics. 2024.
https://www.cell.com/cell-genomics/fulltext/S2666-979X(24)00069-7
Rattus norvegicus has been used in many fields of study related to human disease; its genome was sequenced shortly after the genomes of Homo sapiens and Mus musculus. Investigators report extensive analyses of the improvements in mRatBN7.2, compared with the previous version. They conducted a broad analysis of a whole-genome sequencing data set of 163 samples from 120 inbred rat strains and substrains. Several additional resources have been created. This new assembly and its associated resources create a more solid platform for research on the many dimensions of physiology, behavior, and pathobiology of rats and can provide more reliable and meaningful translation of findings to human populations. Supported by ORIP (R24OD024617), NHGRI, NHLBI, and NIDA.
Identifying Potential Dietary Treatments for Inherited Metabolic Disorders Using Drosophila Nutrigenomics
Martelli et al., Cell Reports. 2024.
https://www.sciencedirect.com/science/article/pii/S221112472400189X?via%3Dihub=
Inherited metabolic disorders are known to cause severe neurological impairment and child mortality and can sometimes respond to dietary treatment; however, a suitable paradigm for testing diets is lacking for developing effective dietary treatment. In this study, researchers found that 26 of 35 Drosophila amino acid disorder models screened for disease–diet interactions displayed diet-altered development and/or survival. Among these models, researchers showed that dietary cysteine depletion normalizes metabolic profile and rescues development, neurophysiology, behavior, and life span in a model for isolated sulfite oxidase deficiency. These findings demonstrate the value of using Drosophila in studying diet-sensitive metabolic disorders and developing potential dietary therapies. Supported by ORIP (R24OD031447) and NHGRI.
Identification of Constrained Sequence Elements Across 239 Primate Genomes
Kuderna et al., Nature. 2024.
https://pubmed.ncbi.nlm.nih.gov/38030727/
Functional genomic elements that have acquired selective constraints specific to the primate order are prime candidates for understanding evolutionary changes in humans, but the selective constraints specific to the phylogenetic branch from which the human species ultimately emerged remain largely unidentified. Researchers constructed a genome-wide multiple sequence alignment of 239 primate species to better characterize constraint at noncoding regulatory sequences in the human genome. Their work reveals noncoding regulatory elements that are under selective constraint in primates but not in other placental mammals and are enriched for variants that affect human gene expression and complex traits in diseases. These findings highlight the important role of recent evolution in regulatory sequence elements differentiating primates, including humans, from other placental mammals. Supported by ORIP (P40OD024628), NHGRI, NIA, and NICHD.
Newly Identified Roles for PIEZO1 Mechanosensor in Controlling Normal Megakaryocyte Development and in Primary Myelofibrosis
Abbonante et al., American Journal of Hematology. 2024.
https://pubmed.ncbi.nlm.nih.gov/38165047/
Mechanisms through which mature megakaryocytes (Mks) and their progenitors sense the bone marrow extracellular matrix to promote lineage differentiation are only partially understood. The authors report that PIEZO1, a mechanosensitive cation channel, is expressed in mouse and human Mks, and activation of PIEZO1 increased the number of immature Mks in mice. Piezo1/2 knockout mice show an increase in Mk size and platelet count, both at basal state and upon marrow regeneration. Together, these data suggest that PIEZO1 places a brake on Mk maturation and platelet formation in physiology, and its upregulation might contribute to aggravating disease. Supported by ORIP (K01OD025290), NHGRI, NHLBI, and NCATS.
The Monarch Initiative in 2024: An Analytic Platform Integrating Phenotypes, Genes and Diseases Across Species
Putman et al., Nucleic Acids Research. 2024.
https://pubmed.ncbi.nlm.nih.gov/38000386/
The Monarch Initiative aims to bridge the gap between the genetic variations, environmental determinants, and phenotypic outcomes critical for translational research. The Monarch app provides researchers access to curated data sets with information on genes, phenotypes, and diseases across species and advanced analysis tools for such diverse applications as variant prioritization, deep phenotyping, and patient profile matching. Researchers describe upgrades to the app, including scalable cloud-based infrastructure, simplified data ingestion and knowledge graph integration systems, enhanced data mapping and integration standards, and a new user interface with novel search and graph navigation features. A customized plugin for OpenAI’s ChatGPT allows the use of large language models to interrogate knowledge in the Monarch graph and increase the reliability of the responses of Monarch’s analytic tools. These upgrades will enhance clinical diagnosis and the understanding of disease mechanisms. Supported by ORIP (R24OD011883), NLM, and NHGRI.
Whole Genome Analysis for 163 gRNAs in Cas9-Edited Mice Reveals Minimal Off-Target Activity
Peterson et al., Communications Biology. 2023.
https://www.nature.com/articles/s42003-023-04974-0
CRISPR/Cas9 genome editing offers potential as a treatment for genetic diseases in humans. Using whole-genome sequencing, investigators assessed the occurrence of Streptococcus pyogenes Cas9–induced off-target mutagenesis in Cas9-edited founder mice. Sequencing and computational analysis indicate that the risk of Cas9 cutting at predicted off-target sites is lower than random genetic variation introduced into the genomes of inbred mice through mating. These findings will inform future design and use of Cas9-edited animal models and can provide context for evaluating off-target potential in genetically diverse patient populations. Supported by ORIP (UM1OD023221, UM1OD023222) and NHGRI.