Therefore, using a mouse line where the expression of CRE recombinase is driven by the rhodopsin promoter30, we generated Bbs8floxed/floxed; Rho-Cre+ mice, in which BBS8 proteins are specifically deleted in photoreceptor cells, to investigate whether retinal degeneration triggered by the loss of BBSome function in photoreceptors alone causes the intrusion of horizontal cell processes into the outer nuclear layer. The gene discussed is TTC8; the disease is retinal degeneration.