Selected Grantee Publications
Mechanical Force of Uterine Occupation Enables Large Vesicle Extrusion From Proteostressed Maternal Neurons
Wang et al., eLife. 2024.
https://pubmed.ncbi.nlm.nih.gov/39255003
This study investigates how mechanical forces from uterine occupation influence large vesicle extrusion (exopher production) from proteostressed maternal neurons in Caenorhabditis elegans. Exophers, previously found to remove damaged cellular components, are poorly understood. Researchers demonstrate that mechanical stress significantly increases exopher release from touch receptor neurons (i.e., ALMR) during peak reproductive periods, coinciding with egg production. Genetic disruptions reducing reproductive activity suppress exopher extrusion, whereas interventions promoting egg retention enhance it. These findings reveal that reproductive and mechanical factors modulate neuronal stress responses, providing insight on how systemic physiological changes affect neuronal health and proteostasis, with broader implications for reproductive-neuronal interactions. Supported by ORIP (R24OD010943, P40OD010440), NIA, and NIGMS.
The Power of the Heterogeneous Stock Rat Founder Strains in Modeling Metabolic Disease
Wagner et al., Endocrinology. 2023.
https://pubmed.ncbi.nlm.nih.gov/37882530/
Metabolic diseases are a host of complex conditions, including obesity, diabetes mellitus, and metabolic syndrome. Endocrine control systems (e.g., adrenals, thyroid, gonads) are causally linked to metabolic health outcomes. In this study, investigators determined novel metabolic and endocrine health characteristics in both sexes of six available substrains similar to the N/NIH Heterogeneous Stock (HS) rat founders. This deep-phenotyping protocol provides new insight into the exceptional potential of the HS rat population to model complex metabolic health states. The following hypothesis was tested: The genetic diversity in the HS rat founder strains represents a range of endocrine health conditions contributing to the diversity of cardiometabolic disease risks exhibited in the HS rat population. Supported by ORIP (R24OD024617), NHLBI, NIGMS and NIDDK.
A Comprehensive Drosophila Resource to Identify Key Functional Interactions Between SARS-CoV-2 Factors and Host Proteins
Guichard et al., Cell Reports. 2023.
https://pubmed.ncbi.nlm.nih.gov/37480566/
To address how interactions between SARS-CoV-2 factors and host proteins affect COVID-19 symptoms, including long COVID, and facilitate developing effective therapies against SARS-CoV-2 infections, researchers reported the generation of a comprehensive set of resources, mainly genetic stocks and a human cDNA library, for studying viral–host interactions in Drosophila. Researchers further demonstrated the utility of these resources and showed that the interaction between NSP8, a SARS-CoV-2 factor, and ATE1 arginyltransferase, a host factor, causes actin arginylation and cytoskeleton disorganization, which may be relevant to several pathogenesis processes (e.g., coagulation, cardiac inflammation, fibrosis, neural damage). Supported by ORIP (R24OD028242, R24OD022005, R24OD031447), NIAID, NICHD, NIGMS, and NINDS.
Resolution of Structural Variation in Diverse Mouse Genomes Reveals Chromatin Remodeling due to Transposable Elements
Ferraj et al., Cell Genomics. 2023.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10203049/
Diverse inbred mouse strains are important biomedical research models, yet genome characterization of many strains is fundamentally lacking in comparison with humans. Here, investigators used long-read whole genome sequencing to assemble the genomes of 20 diverse inbred laboratory strains of mice. From whole-genome comparisons, they generated a sequence-resolved callset of 413,758 structural variants. These data are presented as a comprehensive resource that can be used for future genomic studies, aid in modeling and studying the effects of genetic variation, and enhance genotype-to-phenotype research. Supported by ORIP (R24OD021325), NCI, NIGMS, and NHGRI.
Two Neuronal Peptides Encoded from a Single Transcript Regulate Mitochondrial Complex III in Drosophila
Bosch et al., eLife. 2022.
https://www.doi.org/10.7554/eLife.82709
Transcripts with small open-reading frames (smORFs) are underrepresented in genome annotations. Functions of peptides encoded by smORFs are poorly understood. The investigators systematically characterized human-conserved smORF genes in Drosophila and found two peptides, Sloth1 and Sloth2, that are highly expressed in neurons. They showed that Sloth1 and Sloth2 are paralogs with high sequence similarity but are not functionally redundant. Loss of either peptide resulted in lethality, impaired mitochondrial function, and neurodegeneration. This work suggests the value of phenotypic analysis of smORFs using Drosophila as a model. Supported by ORIP (R24OD019847), NHGRI, and NIGMS.
Rbbp4 Loss Disrupts Neural Progenitor Cell Cycle Regulation Independent of Rb and Leads to Tp53 Acetylation and Apoptosis
Schultz-Rogers et al., Developmental Dynamics. 2022.
https://www.doi.org/10.1002/dvdy.467
Retinoblastoma binding protein 4 (Rbbp4) is a component of transcription regulatory complexes that control cell cycle gene expression by cooperating with the Rb tumor suppressor to block cell cycle entry. The authors used genetic analysis to examine the interactions of Rbbp4, Rb, and Tp53 in zebrafish neural progenitor cell cycle regulation and survival. Rbbp4 is upregulated across the spectrum of human embryonal and glial brain cancers, and it is essential for zebrafish neurogenesis. Rbbp4 loss leads to apoptosis and γ-H2AX in the developing brain that is suppressed by tp53 knockdown or maternal zygotic deletion. Mutant retinal neural precursors accumulate in M phase and fail to initiate G0 gene expression. Rbbp4; Rb1 double mutants show an additive effect on the number of M phase cells. The study demonstrates that Rbbp4 is necessary for neural progenitor cell cycle progression and initiation of G0, independent of Rb, and suggests that Rbbp4 is required for cell cycle exit and contributes to neural progenitor survival. Supported by ORIP (R24OD020166) and NIGMS.
HDAC Inhibitor Titration of Transcription and Axolotl Tail Regeneration
Voss et al., Frontiers in Cell and Development Biology. 2021.
https://pubmed.ncbi.nlm.nih.gov/35036404/
New patterns of gene expression are enacted and regulated during tissue regeneration. Romidepsin, an FDA-approved HDAC inhibitor, potently blocks axolotl embryo tail regeneration by altering initial transcriptional responses to injury. Regeneration inhibitory concentrations of romidepsin increased and decreased the expression of key genes. Single-nuclei RNA sequencing at 6 HPA illustrated that key genes were altered by romidepsin in the same direction across multiple cell types. These results implicate HDAC activity as a transcriptional mechanism that operates across cell types to regulate the alternative expression of genes that associate with regenerative success versus failure outcomes. Supported by ORIP (P40OD019794, R24OD010435, R24OD021479), NICHD, and NIGMS.
MIC-Drop: A Platform for Large-scale In Vivo CRISPR Screens
Parvez et al., Science. 2021.
https://pubmed.ncbi.nlm.nih.gov/34413171/
CRISPR screens in animals are challenging because generating, validating, and keeping track of large numbers of mutant animals is prohibitive. These authors introduce Multiplexed Intermixed CRISPR Droplets (MIC-Drop), a platform combining droplet microfluidics, single-needle en masse CRISPR ribonucleoprotein injections, and DNA barcoding to enable large-scale functional genetic screens in zebrafish. In one application, they showed that MIC-Drop could identify small-molecule targets. Furthermore, in a MIC-Drop screen of 188 poorly characterized genes, they discovered several genes important for cardiac development and function. With the potential to scale to thousands of genes, MIC-Drop enables genome-scale reverse genetic screens in model organisms. Supported by ORIP (R24OD017870), NIGMS, and NHLBI.
Loss of Gap Junction Delta-2 (GJD2) Gene Orthologs Leads to Refractive Error in Zebrafish
Quint et al., Communications Biology. 2021.
https://pubmed.ncbi.nlm.nih.gov/34083742/
Myopia is the most common developmental disorder of juvenile eyes. Although little is known about the functional role of GJD2 in refractive error development, the authors find that depletion of gjd2a (Cx35.5) or gjd2b (Cx35.1) orthologs in zebrafish cause changes in eye biometry and refractive status. Their immunohistological and scRNA sequencing studies show that Cx35.5 (gjd2a) is a retinal connexin; its depletion leads to hyperopia and electrophysiological retina changes. They found a lenticular role; lack of Cx35.1 (gjd2b) led to a nuclear cataract that triggered axial elongation. The results provide functional evidence of a link between gjd2 and refractive error. Supported by ORIP (R24OD026591), NIGMS, and NINDS.
Cell-Specific Transcriptional Control of Mitochondrial Metabolism by TIF1γ Drives Erythropoiesis
Rossmann et al., Science. 2021.
https://pubmed.ncbi.nlm.nih.gov/33986176/
Transcription and metabolism both influence cell function but dedicated transcriptional control of metabolic pathways that regulate cell fate has rarely been defined. The authors discovered that inhibition of the pyrimidine biosynthesis enzyme dihydroorotate dehydrogenase (DHODH) rescues erythroid differentiation in bloodless zebrafish moonshine (mon) mutant embryos defective for transcriptional intermediary factor 1 gamma (tif1γ). Upon tif1γ loss, CoQ levels are reduced, and a high succinate/α-ketoglutarate ratio leads to increased histone methylation. A CoQ analog rescues mon's bloodless phenotype. These results demonstrate that mitochondrial metabolism is a key output of a lineage transcription factor that drives cell fate decisions in the early blood lineage. Supported by ORIP (R24OD017870), NIGMS, NHLBI, and NCI.