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(11)

EP 0 970 193 A1

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(43) Date of publication: 12.01.2000 Bulletin 2000/02 (21) Application number: 97936193.8 (22) Date of filing: 24.07.1997

(51) International Patent Classification (IPC)7: C12N 9/34, C12N 1/21, C12N 15/63, C12N 15/09 (86) International application number: PCT/US9712/983 (87) International publication number: WO 9803/639 (29.01.1998 Gazette 1998/04)

(84) Designated Contracting States: AT BE CH DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE (30) Priority: 24.07.1996 US 22578 P 02.08.1996 US 23077 P (71) Applicant: Iowa State UniversityResearch Foundation, Inc. Ames, IA 50011-2131 (US)

(72) Inventors: ALLEN, Martin Ames, IA 50010 (US) FANG, Tsuei-Yun Ames, IA 50014 (US) LI, Yuxing Ames, IA 50010 (US) LIU, Hsuan-Liang Ames, IA 50014 (US) CHEN, Hsiu-Mei Taipei (TW) COUTINHO, Pedro,c/o Mme Francois Olympie 4900 Angers (FR) HONZATKO, Richard Ames, IA 50014 (US) FORD Clark Ames IA 50014 (US) (74) Representative: Austin, Hedley William  Urquhart-Dykes & LordAlexandra House1 Alexandra Road SwanseaWales SA1 5ED SwanseaWales SA1 5ED (GB)