supported by the National Natural Science Foundation of China (No. 30670923);the Natural Science Foundationof Shandong Province (No. 2006ZRB01898);the Research Startup Fund for Importing Talents of Ocean University of China
supported by the Biotechnology and Biological Sciences Research Council and the Cystic Fibrosis Trust.H Li was supported by EuroCareCF(LSHM-CT-2005-018932)while J-H Chen and Z Xu were supported by scholarships from the University of Bristol and ORS awards from Universities UK.