Time course of body weight during infection. After challenge with P. aeruginosa all animal groups lost weight during the first 24 hours p.i. Young B6 and CftrMHH mice started to regain weight directly thereafter, although this increase was small and both groups had not reached their initial weight by the end of the experiments (A). Weight loss was more pronounced in the old B6 and CftrMHH mice that also did not regain their initial weight by 192 hours p.i. In both CF mouse models CF mice younger than 3 months displayed a reduced body weight compared to their wild type littermates. This tendency became more pronounced in adult C57BL6/J, but not FABP mice thus showing an anthropometric CF phenotype in the former, but not in the latter strain. Please note the different initial values of young and old mice and the stronger impact of gender in the old mice, reflected in the large error bars of old CftrMHH, old CftrKO and WT mice (A, B). Since the group of old CftrMHH mice was exclusively formed by male animals, less pronounced intragroup differences were noted (A, grey line with triangles).