genetic copy protection

[David Honig]

A patent on a means to produce seeds which germinate, but
which produce plants whose seeds are sterile, was
reviewed in Science, p 850, 30 Oct 98 vol 282.

The trick is that the seeds are genetically engineered, 
and the seeds are 'activated' by an antibiotic (which
acts like a signal).  The purpose is to copy-protect
other engineered genes in the organism.

US pat 5,723,765

David Honig

  "When horsemeat is outlawed, only outlaws will eat horsemeat"