Fig. 5. Electroporation of Ptc1^loop2 effectively blocks Shh signal transduction in the central retina. (A-C) Coronal sections of E16.5 retinas electroporated with EGFP and Ptc1^loop2 (B,C) or EGFP alone (A) and immunostained with anti-Isl2 (C-RGCs) or anti-Zic2 (I-RGCs, arrows). (D) Quantitative RT-PCR analysis of Ptc1, Ptc2 and Hip1 mRNA levels. Values were normalised to 18S rRNA. In Ptc1^loop2-electroporated retinas, the endogenous levels of Ptc1 (Ptc1 3'UTR), Ptc2 and Hip1 mRNA are significantly reduced. Primers recognising the Ptc1^loop2 form (Ptc1) confirmed effective plasmid transduction. Values represent the mean ± s.e.m. of two independent experiments performed in triplicate. ^*P<0.05,^**P<0.01 (Student's unpaired t-test). Scale bar: 200 µm.