Fig. 5.

The expression patterns of TRPM1, Gβ₅, and regulator of G protein signaling (RGS) 11 are abnormal in mGluR6-null mice. A: TRPM1 staining in sections of WT and mGluR6-null (KO) retinas. The brightly stained puncta that decorate the dendritic tips of ON bipolar cells disappear in null retina. Insets show magnified areas of the OPL. Cyan brackets indicate the row of puncta under a cone pedicle. For A–C, fixation and immunostaining of WT and mGluR6-null retinas were performed in parallel, and images were taken with the same settings (scale bars = 10 μm). B and C: immunostaining for Gβ₅ (B) and RGS11 (C) shows highly diminished expression at the dendritic tips of null ON bipolar cells. D: immunostaining intensity ratios of null to WT retina for TRPM1, Gβ₅, and RGS11 in OPL, INL, IPL-ON, and the sum of these layers + the OFF sublamina (all layers). Each average comes from 3–5 images. The ratio of TRPM1 band intensities (normalized to actin) of KO/WT in Western blots is also shown. E: intensity distribution of puncta that meet the criteria for the automated count by Volocity. The average puncta intensity for null retina (dotted line) was lower than that for WT (solid line) (data are from one set). F: volume distribution of the same puncta as in E. Puncta in the null retina were smaller than those in WT.