Fig. 5. Alb-Cre lineage labelling. (A) Newborn Alb-Cre/R26R lacZ mouse stained with X-gal. The gall bladder (g) and bile duct system are labelled, as is a piece of liver left attached in the hilar region (h). The pancreas (p) is virtually unlabelled, the visible blue being surface background stain and a small part of the pancreatic duct; d, duodenum. (B,B',B") Section showing an insulin-positive cell labelled with X-gal in the duct epithelium. Bar, 20 µm.