Selected Grantee Publications
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- 21 results found
- Aquatic Vertebrate Models
- 2021
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.
Identification of Basp1 as a Novel Angiogenesis-regulating Gene by Multi-Model System Studies
Khajavi et al., FASEB Journal. 2021.
https://pubmed.ncbi.nlm.nih.gov/33899275/
The authors previously used genetic diversity in inbred mouse strains to identify quantitative trait loci (QTLs) responsible for differences in angiogenic response. Employing a mouse genome-wide association study (GWAS) approach, the region on chromosome 15 containing Basp1 was identified as being significantly associated with angiogenesis in inbred strains. To investigate its role in vivo, they knocked out basp1 in transgenic kdrl:zsGreen zebrafish embryos using a widely adopted CRISPR-Cas9 system. They further showed that basp1 promotes angiogenesis by upregulating β-catenin gene and the Dll4/Notch1 signaling pathway. These results provide the first in vivo evidence to indicate the role of basp1 as an angiogenesis-regulating gene. Supported by ORIP (R24OD017870) and NEI.
Characterization of Axolotl Lampbrush Chromosomes by Fluorescence In Situ Hybridization and Immunostaining
Keinath et al., Experimental Cell Research. 2021.
https://pubmed.ncbi.nlm.nih.gov/33675804/
The lampbrush chromosomes (LBCs) in oocytes of the Mexican axolotl (Ambystoma mexicanum) were identified by their relative lengths and predicted centromeres; they have never been associated completely with the mitotic karyotype, linkage maps, or genome assembly. The authors identified 9 of the axolotl LBCs using RNA sequencing to identify actively transcribed genes and 13 bacterial artificial clone probes containing pieces of active genes. This study presents a simple and reliable way to identify each axolotl LBC cytologically and to anchor chromosome-length sequences to the LBCs by immunostaining and fluorescence in situ hybridization. This data will facilitate a more detailed analysis of LBC loops. Supported by ORIP (P40OD019794, R24OD010435) and NIGMS.
The Giant Axolotl Genome Uncovers the Evolution, Scaling, and Transcriptional Control of Complex Gene Loci
Schloissnig et al., PNAS. 2021.
https://pubmed.ncbi.nlm.nih.gov/33827918/
Vertebrates harbor recognizably orthologous gene complements but vary 100-fold in genome size. How chromosomal organization scales with genome expansion is unclear, and how acute changes in gene regulation, as during axolotl limb regeneration, occur in the context of a vast genome has remained a riddle. Here, Schloissnig et al. describe the chromosome-scale assembly of the giant, 32 Gb axolotl genome. Hi-C contact data revealed the scaling properties of interphase and mitotic chromosome organization. Analysis of the assembly yielded understanding of the evolution of large, syntenic multigene clusters, including the major histocompatibility complex (MHC) and the functional regulatory landscape of the fibroblast growth factor 8 (Axfgf8) region. The axolotl serves as a primary model for studying successful regeneration. Supported by ORIP (R24OD010435, P40OD019794).
Bilateral Visual Projections Exist in Non-Teleost Bony Fish and Predate the Emergence of Tetrapods
Vigouroux et al., Science. 2021.
https://pubmed.ncbi.nlm.nih.gov/33833117/
In most vertebrates, camera-style eyes contain retinal ganglion cell neurons that project to visual centers on both sides of the brain. However, in fish, ganglion cells were thought to innervate only the contralateral side, suggesting that bilateral visual projections appeared in tetrapods. Here, Vigouroux et al. showed that bilateral visual projections exist in non-teleost fishes and that the appearance of ipsilateral projections does not correlate with terrestrial transition or predatory behavior. However, overexpression of human ZIC2 induces ipsilateral visual projections in zebrafish. Therefore, the existence of bilateral visual projections likely preceded the emergence of binocular vision in tetrapods. Supported by ORIP (R01OD011116).
The SARS-CoV-2 Receptor and Other Key Components of the Renin-Angiotensin-Aldosterone System Related to COVID-19 are Expressed in Enterocytes in Larval Zebrafish
Postlethwait et al., Biology Open. 2021.
https://bio.biologists.org/content/10/3/bio058172.article-info
Hypertension and respiratory inflammation are exacerbated by the Renin-Angiotensin-Aldosterone System (RAAS), which normally protects from dropping blood pressure via Angiotensin II (Ang II) produced by the enzyme Ace. The Ace paralog Ace2 degrades Ang II and serves as the SARS-CoV-2 receptor. To exploit zebrafish to understand the relationship of RAAS to COVID-19, the group conducted genomic and phylogenetic analyses. Results identified a type of enterocyte as the expression site of zebrafish orthologs of key RAAS components, including the SARS-CoV-2 co-receptor. Results identified vascular cell subtypes expressing Ang II receptors and identified cell types to exploit zebrafish as a model for understanding COVID-19 mechanisms. Supported by ORIP (R24OD026591, R01OD011116), NIGMS, NICHD.
A Chromosome-Level Genome of Astyanax mexicanus Surface Fish for Comparing Population-Specific Genetic Differences Contributing to Trait Evolution
Warren et al., Nature Communications. 2021.
https://pubmed.ncbi.nlm.nih.gov/33664263/
Identifying the genetic factors that underlie complex traits is central to understanding the mechanistic underpinnings of evolution. Cave-dwelling Astyanax mexicanus populations are well adapted to subterranean life and many populations appear to have evolved troglomorphic (morphological adaptation of an animal to living in the constant darkness of caves) traits independently, while the surface-dwelling populations can be used as a proxy for the ancestral form. Warren et al. present a high-resolution, chromosome-level surface fish genome, enabling the first genome-wide comparison between surface fish and cavefish populations. Using this resource, they performed quantitative trait locus (QTL) mapping analyses and found new candidate genes for eye loss (dusp26). They also generated the first genome-wide evaluation of deletion variability across cavefish populations to gain insight into this potential source of cave adaptation. The surface fish genome reference now provides a more complete resource for comparative, functional and genetic studies of drastic trait differences within a species. Supported by ORIP (R24OD011198), NIA, NICHD, NIGMS, amd NIDCR.
Larval Zebrafish Use Olfactory Detection of Sodium and Chloride to Avoid Salt Water
Herrera et al., Current Biology. 2021.
https://pubmed.ncbi.nlm.nih.gov/33338431/
Zebrafish are freshwater fish unable to tolerate high-salt environments and would benefit from neural mechanisms that enable the navigation of salt gradients to avoid high salinity. Yet zebrafish lack epithelial sodium channels, the primary conduit land animals use to taste sodium. This suggests fish may possess novel, undescribed mechanisms for salt detection. In the present study, the authors show that zebrafish indeed respond to small temporal increases in salt by reorienting more frequently. In summary, this study establishes that zebrafish larvae can navigate and thus detect salinity gradients and that this is achieved through previously undescribed sensory mechanisms for salt detection. Supported by ORIP (R43OD024879, R44OD024879) and NINDS.
Acoustofluidic Rotational Tweezing Enables High-Speed Contactless Morphological Phenotyping of Zebrafish Larvae
Chen et al., Nature Communications. 2021.
https://pubmed.ncbi.nlm.nih.gov/33602914/
These authors demonstrate an acoustofluidic rotational tweezing platform that enables contactless, high-speed, 3D multispectral imaging and digital reconstruction of zebrafish larvae for quantitative phenotypic analysis. The acoustic-induced polarized vortex streaming achieves contactless and rapid (~1 s/rotation) rotation of zebrafish larvae enabling multispectral imaging of the zebrafish body and internal organs. They developed a 3D reconstruction pipeline that yields accurate 3D models based on the multi-view images for quantitative evaluation. With its contactless nature and advantages in speed and automation, the acoustofluidic rotational tweezing system has the potential to be a valuable asset for developmental biology and pre-clinical drug development in pharmacology. Supported by ORIP (R43OD024963), NCI, and NIGMS.
Trim-Away Mediated Knock Down Uncovers a New Function for Lbh During Gastrulation of Xenopus laevis
Weir et al., Developmental Biology. 2021.
https://pubmed.ncbi.nlm.nih.gov/33159936/
The protein Lbh was identified as necessary for cranial neural crest cell migration in Xenopus. To investigate its role in embryonic events, the authors employed the technique "Trim-Away" to degrade this maternally deposited protein. Trim-Away utilizes the E3 ubiquitin ligase trim21 to degrade proteins targeted with an antibody. Early knockdown of Lbh in Xenopus results in defects in gastrulation that present with a decrease in fibronectin matrix assembly, an increase in mesodermal cell migration and decrease in endodermal cell cohesion. The technique is also effective on a second abundant maternal Protein Kinase C And Casein Kinase Substrate In Neurons 2. Supported by ORIP (R24OD021485) and NIDCR.