Figure 2. Scrib mRNA distribution in control retina and protein localizations in adult retina and during development from control and Trp1/Tag mice using immunohistochemistry. A and B show Scrib mRNA localization whereas C-P show Scrib protein distribution in adult mouse retina from the control mouse (C-E) and the Trp1/Tag mouse model (F-P) at P15 (F), P20 (G,H), P25 (I-K), P30 (L-N), and three months (O,P). A and C show the negative controls for B and D, respectively. In the retina, the Scrib mRNA and protein were observed in the ganglion cell layer (GCL), the inner nuclear layer (INL), the outer nuclear layer (ONL), and the outer plexiform layer (OPL). No mRNA expression was detected in the inner plexiform layer, but its protein was detected (in the IPL). Very strong levels of expression were detected in the photoreceptor inner segments (IS) and the external limiting membrane (elm). We also detected Scrib in the retinal pigment epithelium (RPE), choroidal melanocytes, and choroidal vascular cells (Ch). The neural retina continued staining positive for the Scrib protein in ocular tumor development in Trp1/Tag mice (F-P). However, from P15, strong staining was lost in the OPL (F,G,I,L). Scrib immunolabeling in the nuclear layers appeared to be more diffuse rather than restricted to cell membranes as observed in the control retina (F,G,I,L). The thickening of the pigmentary epithelium (RPE) was also positive for Scrib, which was predominantly localized to the cell membrane but also present in the cytoplasm (F). In addition, low levels of Scrib seemed to be present in the uvea (Ch; M). The intensity of the Scrib protein labeling in tumoral cells was markedly reduced and no longer restricted to cell membranes as described for P25. Scrib protein was detectable in tumor cells from P20 (H,K). However, at P30 and three months, no significant Scrib immunolabeling could be detected in tumoral cells (N,P).