Selected Grantee Publications
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- 5 results found
- Aquatic Vertebrate Models
- Neurological
- 2021
Precise Visuomotor Transformations Underlying Collective Behavior in Larval Zebrafish
Harpaz et al., Nature Communications. 2021.
https://www.nature.com/articles/s41467-021-26748-0
Sensory signals from neighbors, analyzed in the visuomotor stream of animals, is poorly understood. The authors studied aggregation behavior in larval zebrafish and found that over development larvae transition from over dispersed groups to tight shoals. Young larvae turn away from virtual neighbors by integrating and averaging retina-wide visual occupancy within each eye, and by using a winner-take-all strategy for binocular integration. Observed algorithms accurately predict group structure over development. These findings allow testable predictions regarding the neuronal circuits underlying collective behavior in zebrafish. Supported by ORIP (R43OD024879, R44OD024879) and NINDS.
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).
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.
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.
Endogenous Zebrafish Neural Cre Drivers Generated by CRISPR/Cas9 Short Homology Directed Targeted Integration
Almeida et al., Scientific Reports. 2021.
https://pubmed.ncbi.nlm.nih.gov/33462297/
Almeida et al. previously reported precision targeted integration of reporter DNA in zebrafish using CRISPR/Cas9. Here, they isolated zebrafish Cre recombinase drivers. A 2A-Cre recombinase transgene with 48 bp homology arms was targeted into proneural genes ascl1b, olig2 and neurod1. They observed high rates of germline transmission from 10 to 100% (10% olig2; 20% neurod1; 100% ascl1b). The lines Tg(ascl1b-2A-Cre)is75, Tg(olig2-2A-Cre)is76, and Tg(neurod1-2A-Cre)is77 expressed functional Cre recombinase in the cell populations. Results demonstrate Cre recombinase expression is driven by the native promoter and regulatory elements of targeted genes. This approach is a cost-effective method to generate cell type specific zebrafish Cre and CreERT2 drivers. Supported by ORIP (R24OD020166).