Figure 3. mPins mRNA localization in the postnatal and adult retina by in situ PCR hybridization. mPins labeling is shown in the postnatal retina at P3 (A) and P12 (B), and in the adult retina (D and E). C and F are higher magnifications of B and E, respectively. G and H show negative controls at P3 and in adult retina, respectively, using the mPins sense probe. At the P3 stage, significant mPins mRNA labeling is detected in the neuroblastic (NbL) and ganglion cell layers (GCL; A). In the retina, at the P12 stage, significant mPins mRNA is detected in the GCL, the inner nuclear layer (INL), the outer nuclear layer (ONL), and in the inner segments of the photoreceptors (IS; B). High magnification of retina at this stage shows that mPins mRNA labeling is more intense on either side of the INL (C, asterisks). No significant labeling is observed in either of the plexiform layers (B and C). A similar pattern of mPins expression is observed in the adult retina (D and E). mPins mRNA is detected in cell bodies on sections of the optic nerve (ON; E). Significant mPins labeling is also detected at this stage in the retinal pigment epithelium (RPE) and choroidal melanocytes (Ch; F).