Journal: bioRxiv
Article Title: Validation of Duchenne muscular dystrophy candidate modifiers using a CRISPR-Cas9-based approach in zebrafish
doi: 10.1101/2025.05.20.655139
Figure Lengend Snippet: Development of a Zebrafish CRISPR/Cas9 pipeline to assess functional impact of DMD modifier candidates . (A) Adult fish heterozygous for dmd are intercrossed to generate embryos for the screen. Because DMD in zebrafish follows an autosomal recessive inheritance pattern, one-quarter of the intercross progeny are homozygous dmd mutants ( dmd-/- ), all of which are identifiable using birefringence imaging by 4 dpf due to the presence of muscle lesions. Homozygous wild-type ( dmd+/+ ) and heterozygous dmd ( dmd+/- ) fish are indistinguishable. Embryos are injected by the 1-cell stage with modifier-targeting CRISPR and Cas9 protein or raised as uninjected controls. All fish are assayed for DMD onset between 2-4 dpf using live birefringence imaging. At 4 dpf, all fish are fixed, birefringence imaged, and genotyped via HRMA. (B, B’) Representative examples of wild-type (WT, top) and dmd-/- mutant (bottom) fish imaged via birefringence at 4 dpf. The boxes in B are shown magnified in B’. Wild-type fish show strong, uniform birefringence, whereas dmd mutant fish have variably-sized non-birefringence patches indicating dystrophic lesions (white arrows). Fish containing one or more lesion, regardless of lesion size or number, are scored as dystrophic in the onset assay.
Article Snippet: DNA was extracted from adult fin tissue or whole larvae as described above and 1ul was used as template in a 10ul HRMA reaction (BioRad 172-5112) in a CFX Duet Real-Time PCR System (#12016265) and analyzed using BioRad Precision Melt Analysis Software.
Techniques: CRISPR, Functional Assay, Imaging, Injection, Mutagenesis