Decreased levels of PALS1 in the retina after conditional gene silencing. A, Schematic representation of shPals1-RxCre retinas after Cre-mediated recombination. After Cre recombination, the U6 promoter drives the expression of shRNA against the Pals1 gene as illustrated. The small arrow indicates the insertion of the short hairpin Pals1 sequence behind the second loxP. PGK, Phosphoglycerate kinase promoter; PURO, puromycin gene; U6, U6 promoter. B, Genotyping of the mice (RxCre, shPals1, and shPals1-RxCre) was done by long-distance-PCR on genomic DNA isolated from E15 or 3-month-old retinas. The upper PCR bands (1979 bp) are from non-recombined and the lower bands (466 bp) are from recombined DNA products. 3M, 3 Months of age; E15, embryonic day 15. C, PALS1 protein levels were decreased to 52 ± 3% in P6 shPals1-RxCre retinas. Total retina cell lysates were used for SDS-PAGE and Western blot analysis. PALS1 antibody was used to detect PALS1 protein in the retinas and actin antibody was used for loading control. Expression levels were normalized to actin.