Zebrafish cdh23 Affects Rod Cell Phototransduction Through Regulating Ca2+ Transport and MAPK Signaling Pathway.

Mutations in the pathogenic gene CDH23 are known to cause Usher syndrome, affecting both auditory and visual functions. Our previous results provided valuable insights into the mechanisms underlying congenital hearing loss associated with CDH23 mutations. However, the molecular mechanisms and signaling pathways that influence vision remain largely unknown. In this study, transcriptional sequencing and bioinformatics analysis were conducted to compare gene expression between the control and cdh23-/-. Additionally, RT-qPCR experiments were performed to further validate the bioinformatics analysis results. The comparative transcriptomic analysis identified differentially expressed genes associated with photoreceptor degeneration and the mitogen-activated protein kinase (MAPK) signaling pathway. Embryos were subjected to hematoxylin and eosin (H&E) staining to assess their histological changes. The results showed that the cdh23-/- retina was morphologically indistinguishable from the control. Apoptosis was assessed using TUNEL staining, which revealed an increase in total cell death in the cdh23-/- retina. Our results revealed that the cell death was induced by Ca2+ and MAPK signaling interactions following photoreceptor degeneration. This study provides insights into the mechanisms underlying the role of cdh23 in vision.