[1] Univ Milan, Dipartimento Fisiol & Biochim Gen, Milan, Italy
[2] Univ Dusseldorf, Inst Bot 3, D-4000 Dusseldorf, Germany
[3] Univ Oxford, Dept Zool, Oxford, England
[4] Lund Univ, Lund, Sweden
[5] Univ Oxford, Dept Biochem, Oxford, England
[6] Royal Holloway Univ London, Sch Biol Sci, Egham, Surrey, England