Abstract
Abstract: :
Purpose: Previous work has demonstrated that RGS9 is expressed in both rods and cones and that RGS9 is essential for normal inactivation of rod and cone phototransduction in mouse. The purpose of the present study is to evaluate the cellular expression of RGS11 in retinal cross-sections of rat and monkey eyes. Methods: A rabbit polyclonal antibody generated against the G-gamma subunit-like domain of RGS11 (RGS11-GGL) was used to evaluate the cellular expression of RGS11 protein in retinal cryosections of paraformaldehyde-fixed Sprague-Dawley rat and cynomolgus monkey eyes. Cellular expression of RGS11-GGL was detected using conventional fluorescent immunocytochemisty techniques. Cone-specific labeling was detected using fluorescent-conjugated peanut agglutinin (PNA). Results: Labeling of RGS11-GGL was detected in cone outer segments of rat and monkey photoreceptors. In monkey, RGS11-GGL and PNA colocalization was observed in every cone examined, but in rat, there appeared to be a subset of PNA-positive cones that showed no RGS11-GGL labeling. RGS11-GGL labeling was restricted to cone outer segments in rat whereas RGS11-GGL labeling was detected throughout the entire cone cell body in monkey. Strong RGS11-GGL labeling was also detected in rat RPE along the basolateral domain, but no labeling was detected in monkey RPE. Conclusions: The present study shows that RGS11 protein is localized in rat and monkey cone outer segments, suggesting a role for RGS11 in cone (but not rod) phototransduction kinetics. Species differences in RGS11 labeling in RPE were also observed, suggesting an additional role for RGS11 function in rat, but not monkey, RPE.
Keywords: immunohistochemistry • photoreceptors • signal transduction