Figure 8

Aberrant horizontal cell processes intrude into the outer nuclear layer in Bbs7^−/− retinas. P21 retinas from Bbs7^−/− and control littermates were probed with anti-calbindin and anti-CtBP2/RIBEYE antibodies. In control retinas (a), the outer nuclear layer lacks immunoreactive signals from both antibodies. In Bbs7^−/− retinas (b, c, d), calbindin-positive horizontal cell processes decorated by ribbon synapses are observed in the outer nuclear layer, frequently spanning the entire thickness of the outer nuclear layer. ONL: outer nuclear layer; OPL: outer plexiform layer; INL: inner nuclear layer.