Fig 8

Transient overexpression of miR-34a sensitizes zebrafish embryos to camptothecin treatment.

(A) mRNAs used for demonstrating miR-34a-mediated repression. miR-34a reporter RNA contains 3 miR-34a sites, which are anti-sense to the miR-34a sequence. EGFP mRNA is a control mRNA for the miR-34a reporter mRNA. TagRFP mRNA is used for normalizing injections. (B) Structure of the miRIDIAN miR-34a mimic. (C) Imaging of miR-34a reporter EGFP injected with a control or miR-34a mimic. (D) Quantification of EGFP/TagRFP signal ratios after control and miR-34a mimic injection at 16 and 28 hpf stages. Two-sample t-tests at both stages have P-values < 0.001 (***). (E) Experimental plan for testing how miR-34a overexpression affects the apoptotic phenotype after DNA damage by gamma-irradiation or by 100 nM camptothecin treatment. (F) Apoptosis and morphology imaging of zebrafish embryos at 30 hpf treated according to the plan in (E) using Acridine Orange (AO). (G) Quantification of the results of DNA damage treatments with a control or miR-34a mimic. Chi-square test on the 100 nM data produced P-value <10⁻¹⁵ as indicated (***).