Generation of the CftrTgH(neoim)Hgumouse model. a) Insertional disruption of the murine Cftr gene and predicted gene structure as described by Dorin et al. (1992). Abbreviations: S, Sal I; H, Hind III; X, Xba I. Map position of the CFneo1 and CFneo2 products is also indicated. b) Genotype analysis of heterozygous cf/+ matings. The probe 1.2H issued in order to identify via Southern hybridisation the congenic mice which carry the insertion. DNAs were digested with Xba I+Sal I and probed with 1.2H. The upper hybridising fragment of 6.6 Kb represents the wild type allele, the lower 5 Kb fragment is diagnostic for the insertional mutation.