An important corn transformation patent was recently issued to inventors affiliated with Pioneer Hi-Bred International, Inc., that highlights the company's early leadership in applying the revolutionary "gene-gun'' technology to agriculture.

US Patent 5,886,244 covers a process for producing a fertile and stably transformed corn plant. One step of the process involves a unique method of preparing corn cells for bombardment that increases the success rate of transformation in those cells. Pioneer filed its application for the patent in June, 1988 -- more than 18 months before others applied for patents in biolistic plant transformation.

"This patent covers a widely applicable and useful technology for which Pioneer continues to pursue broad protection in other pending applications,'' said Herb Jervis, Pioneer vice president and chief intellectual property counsel. "And, by virtue of its early filing date, the patent clearly demonstrates Pioneer's early entry into corn transformation with biolistics.''

Pioneer developed the system for corn transformation using the gene gun. But rights to products derived from bombardment transformation -- including popular insect- and herbicide-resistant hybrids and varieties -- are currently in dispute. DeKalb Genetics sued Pioneer and others over a series of patents DeKalb was granted in 1996. Since then, one of the DeKalb suits has been stayed and two others against Pioneer have been dismissed with prejudice.

The new Pioneer patent could result in dismissal of the remaining suits brought by DeKalb against Pioneer. The patent shows Pioneer had access to and was actively developing the bombardment transformation process long before DeKalb began experiments and, later, filed for its patents.