Table 3. Single photon events provide estimates of wild type and mutant rhodopsin content in the outer segment

An estimation of the proportion of wild type and mutant rhodopsin molecules present in the outer segment can be constructed by sorting of dim flash responses (n=96) into blanks (no response; n=36), step-like photocurrent responses (n=29), single-photon responses (n=21), and combination responses (n=10). First, we assume mutant rhodopsin produces the step-like responses, wild type rhodopsin produces "singles", and a Poisson distribution of events. Then one can vary the probability of mutant rhodopsin (p_Ser347) and wild type rhodopsin (p_wt) in order to produce the observed distribution. The predictions below are based on p_Ser347 equal to 0.58 and p_wt equal 0.42. The number of observed blank responses permits calculating μ, the mean number of events per flash using the Poisson equation.

                      Calculated μ=0.98
                     --------------------
                     Predicted   Observed
                     ---------   --------
Step-like currents     28.6         29
Singles                17.3         21
Combinations           13.6         10