Clinical validation of RCSMS: A rapid and sensitive CRISPR-Cas12a test for the molecular detection of SARS-CoV-2 from saliva.

Peru's holds the highest COVID death rate per capita worldwide. Key to this outcome is the lack of robust, rapid, and accurate molecular tests to circumvent the elevated costs and logistics of SARS-CoV-2 detection via RT-qPCR. To facilitate massive and timely COVID-19 testing in rural and socioeconomically deprived contexts, we implemented and validated RCSMS, a rapid and sensitive CRISPR-Cas12a test for the molecular detection of SARS-CoV-2 from saliva.

Substrate properties of zebrafish Rtn4b/Nogo and axon regeneration in the zebrafish optic nerve.

This study explored why lesioned retinal ganglion cell (RGC) axons regenerate successfully in the zebrafish optic nerve despite the presence of Rtn4b, the homologue of the rat neurite growth inhibitor RTN4-A/Nogo-A. Rat Nogo-A and zebrafish Rtn4b possess characteristic motifs (M1-4) in the Nogo-A-specific region, which contains delta20, the most inhibitory region of rat Nogo-A. To determine whether zebrafish M1-4 is inhibitory as rat M1-4 and Nogo-A delta20, proteins were recombinantly expressed and used as substrates for zebrafish single cell RGCs, mouse hippocampal neurons and goldfish, zebrafish and chick retinal explants.

Cre-inducible site-specific recombination in zebrafish oligodendrocytes.

Background: The conditional Cre/lox system has recently emerged as a valuable tool for studies on both embryonic and adult Zebrafish. Temporal control and site-specific recombination are achieved by using the ligand-inducible CreER and administration of the drug tamoxifen (TAM) or its active metabolite, 4-Hydroxytamoxifen (4-OHT).

Results: Here we report the generation of a transgenic Zebrafish line, which expresses an mCherry-tagged variant of CreER under the control of the myelin basic protein a (mbpa) promoter.

Activation of zebrafish Src family kinases by the prion protein is an amyloid-β-sensitive signal that prevents the endocytosis and degradation of E-cadherin/β-catenin complexes in vivo.

Background: Prions and amyloid-β (Aβ) oligomers trigger neurodegeneration by hijacking a poorly understood cellular signal mediated by the prion protein (PrP) at the plasma membrane. In early zebrafish embryos, PrP-1-dependent signals control cell-cell adhesion via a tyrosine phosphorylation-dependent mechanism.

Results: Here we report that the Src family kinases (SFKs) Fyn and Yes act downstream of PrP-1 to prevent the endocytosis and degradation of E-cadherin/β-catenin adhesion complexes in vivo.

Essential roles of zebrafish rtn4/Nogo paralogues in embryonic development.

Background: As a consequence of gene/genome duplication, the RTN4/Nogo gene has two counterparts in zebrafish: rtn4a and rtn4b. The shared presence of four specific amino acid motifs-M1 to M4-in the N-terminal region of mammalian RTN4, and zebrafish Rtn4b suggests that Rtn4b is the closest homologue of mammalian Nogo-A.

Results: To explore their combined roles in zebrafish development, we characterized the expression patterns of rtn4a and rtn4b in a comparative manner and performed morpholino-mediated knockdowns.