dre-mir-20b: Dre-mir-20b is a type of microRNA that has been studied in relation to embryo development and retinal morphology [PMC6834413]. In a study, it was found that in the 4 uM dre-mir-20b group, the embryo mortality rate was significantly higher and the survival rate was significantly reduced compared to the NC group and wild type group (Table 1) [PMC6834413]. Additionally, the mRNA expressions of FGF2 and GRB2 were significantly lower in the dre-mir-20b group compared to the NC group and wild-type group (Figure 9B) [PMC6834413]. Abnormal retinal morphology was observed in the dre-mir-20b group, characterized by sparse and irregular photoreceptor cells [PMC6834413]. Furthermore, there were more overall morphological abnormalities, particularly a significant reduction in eye volume in the 4 uM dre-mir-20b group (Figure 9A) [PMC6834413]. Immunofluorescence tests showed that FGF2 and GRB2 were expressed in the photoreceptor cell layer, but their expression levels were decreased in the dre-mir-20b group compared to the NC group and wild type group (Figure 10B, 10C) [PMC6834413]. The study used 4 uM dre-mir-20b mimics and corresponding negative control (NC) injected at single cell stage [PMC6834413]. These findings suggest that dre-mir-20b plays a role in embryo development, retinal morphology, and gene expression regulation [PMC6834413].