Figure 4. Effect of media serum on mRNA levels in cultured retinal cells

Visinin, α-transducin, HIOMT, and red opsin mRNA levels in retinal cells cultured with or without serum were assessed. Total RNA (15 μg per lane) extracted from approximately 10⁷ cultured cells or from a pool of 10 embryonic (E10) retinas, was analyzed on northern blot with the indicated ³²P-labeled cDNA probes. A ³²P-labeled 18S rRNA oligonucleotide was used to verify equal RNA loading in the different lanes. A: E7 retinal cells were cultured for two to three days in serum-supplemented medium. Their profile of gene expression is compared with that of neural retinas from E10 embryos. The results are representative of at least eight experiments. B: Duplicate cultures of E7 retinal cells were kept for two days in either basal medium (0.5% bovine serum albumin) or serum-supplemented medium (10% newborn calf serum). A batch of cells cultured for two days in basal medium was transfered to serum-supplemented medium for two additional days.