Developmental stability in a cystic fibrosis mouse model
The aim of this study was to investigate the influence of cystic fibrosis (CF) and chronic experimental lung infection with Pseudomonas aeruginosa on developmental instability and behaviour in the transgenic Cftrtm1Unc -TgN(FABPCFTR) mouse compared to different heterozygote (CFTR+/-) and wildtype (CFTR+/+) controls. Developmental instability measured as fluctuating asymmetry (FA), body weight and open-field behaviour were assessed in CFTR-/-, CFTR+/- and CFTR+/+ mice. FA and different behavioural tests were investigated in relation to tracheotomy and lung infection with P. aeruginosa. Body weight was in general decreased in the CFTR-/- mice and increased in the CFTR+/- mice. CFTR-/- mice had a significantly higher degree of FA (4%-5.5%) than all other groups (1%-3%) (P<0.001), while having cystic fibrosis did not seem to influence the behaviour of these mice indicating that the clinical impact from the model is rather low, which is positive from a welfare point of view. FA and motor performance was influenced by neither the lung infection nor the tracheotomy. Tracheotomy increased the level of fear in the light-dark box (P<0.05), and the lung infection decreased activity in the open field (P<0.05). From this we may conclude that well-being expressed as changed behaviour is a result of the lung infection more than a consequence of the mutation.