[1] Univ E Anglia, Sch Biol Sci, Norwich NR4 7TJ, Norfolk, England
[2] Childrens Hosp Los Angeles, Saban Res Inst, Los Angeles, CA 90027 USA
[3] Natl Jewish Hlth, Dept Pediat, Denver, CO USA
[4] Univ Helsinki, Dept Orthodont, Helsinki, Finland
[5] EMBL CRG Syst Biol Unit, CRG, Barcelona, Spain
[6] Dev Biol Inst Inst Marseilles Luminy, Marseille, France