DNA Plant Technology Corp. announced Monday that it hascreated a "sense" genetic engineering technology to controlripening in tomatoes.

The company (NASDAQ:DNAP) uses its gene suppressionmethod, termed transwitch technology, to insert a segment ofthe ACC synthase gene into tomatoes. This extra gene segmentsomehow inhibits the tomato's production of the gas ethylene,which is primarily responsible for ripening.

"We know that the sense construct we introduce has to betranscribed, and that it has to be greater than 85 percenthomologous to the existing DNA," John Bedbrook, DNAP's vicepresident of R&D, told BioWorld. "The cDNA copy of the sensegene is basically blocking nuclear transcription (of the nativegene)."

DNAP, which has facilities in both Oakland, Calif., andCinnaminson, N.J., plans to enter the commercial market withits genetically engineered tomato in 1994. Prior to that, it willapply to the USDA to deregulate this product, a process thatCalgene Inc. just completed for its engineered (though by"antisense" technology) tomato.

"Delisting from USDA is part and parcel of what we will have todo as we go forward with large-scale production and marketingof our genetically engineered tomato," Bedbrook said. --Jennifer Van Brunt

(c) 1997 American Health Consultants. All rights reserved.