The gap-junction-forming protein connexin36 (Cx36) represents the anatomical substrate of photoreceptor electrical coupling in mammals. and intrinsic to the retina so that under prolonged dark-adapted conditions tracer coupling is broader at night compared to daytime. In the current study we examined whether the modulation of photoreceptor coupling by a circadian clock in CBA/CaJ mouse photoreceptors reflected a change in Cx36 protein expression and/or phosphorylation. We found no significant change in Cx36 expression or in the number of Cx36 gap junction among the conditions examined. However we found that Cx36 phosphorylation is higher under dark-adapted conditions at night than in the daytime and is the lowest under prolonged illumination at any time of the day/night cycle. Our observations are consistent with the view that the circadian clock regulation of photoreceptor electrical coupling is mouse strain-dependent and highlight the critical position of Cx36 phosphorylation in the control of photoreceptor coupling. = 0.289] nature of the cycle [= 0.666] or time in the cycle x nature of the cycle [= 0.190] effects. The average number of gap junction plaques in each condition Imidapril (Tanatril) is illustrated in Figure 1C. ANOVA of the data presented in figure 1C revealed no significant time in the cycle [= 0.694] nature of the cycle [= 0.944] or time in the cycle x nature of the cycle [= 0.935] effects. The phosphorylation state of Cx36 in the OPL was quantified from the percentage of PS293Cx36/pan-Cx36 (observe Kothmann et al. 2009 or Li et al. 2013 for details). We found changes in the phosphorylation state of Cx36 according to the time of day (Fig. 1A 1 ANOVA of the data presented in number 1D exposed significant time in the cycle [< 0.0001] effect and no significant nature of the cycle [= 0.0834] or time in the cycle x nature of the cycle [= 0.575] effects. Therefore the data demonstrate that a circadian clock in CBA/CaJ mouse settings the phosphorylation state of Cx36 so that the connexin is definitely highly phosphorylated during the night or subjective night time and poorly phosphorylated during the day in the dark or subjective day time. In addition our data show that neither Cx36 manifestation nor the number Imidapril (Tanatril) of Cx36 space junctions in the OPL switch with time of day time. Next we tested the effects of light adaptation within the phosphorylation state of Rabbit Polyclonal to GRB2. Cx36 in the middle of subjective day time and subjective night time. Animals were exposed to space lamps (300-500 lux) 1 h or 3 h before sacrifice. Examples of immuno-staining of Cx36 and PS293Cx36 under dark-adapted or light-adapted conditions during subjective day time or night time are demonstrated in number 2A. Averaged ideals of the mean pixel intensity in the red channel under the numerous experimental conditions are illustrated in Number 2B. A two-way ANOVA of the data was performed with time in the cycle as the 1st element (i.e. daytime nighttime) and the lighting conditions as the second element (i.e. dark-adapted light-adapted for 1 h light-adapted for 3 h). ANOVA of the data presented in number 2B exposed no significant time in the cycle [= 0.959] lighting conditions [= 0.155] or time in the cycle x lighting conditions [= 0.781] effects. Averaged ideals of the total quantity of Cx36 plaques and of the phosphorylation claims of OPL Cx36 under the numerous experimental conditions are demonstrated in numbers 2C and 2D respectively. ANOVA of the data presented in number 2C exposed no significant time in the cycle [= 0.857] lighting conditions [= 0.565] or time in the cycle x lighting conditions [= 0.646] effects. Therefore Cx36 manifestation and the number of Cx36 plaques in the OPL were not modified from the lighting conditions. ANOVA of the data presented in number 2D exposed significant time in the cycle [< 0.01] and lighting conditions [< 0.0001] effects but no time in the cycle x Imidapril (Tanatril) lighting conditions [= 0.268] effects. These data demonstrate that photopic light decreases Cx36 phosphorylation in CBA/CaJ photoreceptors on a time Imidapril (Tanatril) level of hours a result in line with our earlier observations in the C57Bl/6J (Li et al. 2013 Conversation Sensory organs are able to encode amounts of information far greater than their output.