Enhancers from the ocs gene

Most of the patents in this group were filed and initially granted to Mycogen Plant Sciences, Lubrizol Enterprises Inc. or Agrigenetics LP and the Commonwealth Scientific and Industrial Research Organization (CSIRO) in the U.S., Europe and Canada. Agrigenetics LP was owned by Mycogen Corp. and Lubrizol Enterprises Inc. but doing business as Mycogen Plant Sciences. Mycogen Plant Sciences later changed its name to Mycogen seeds and is now owned by Dow AgroSciences.  For more information about this patent group or licensing, Dow AgroSciences and CSIRO should be contacted (links are provided in the table on next page).

Approximate scope of protection

The claims of this group of patents encompasses two enhancer elements. One of them is a consensus DNA sequence from the non-transcribed region of the promoter regions of seven opine synthase genes and plant viral promoters from the cauliflower mosaic virus (CaMV), the figwort mosaic virus (FMV) and the carnation etched ring virus (CERV). The 20 bp consensus sequence is: 5′-TGACGTAAGCGATGACGTAA-3′.

The other enhancer element is a 16 bp palindromic sequence isolated from the 5′-untranscribed region of the ocs gene. The nucleotide sequence is 5′-ACGTAAGCGCTTACGT-3′.

The enhancer elements are linked to any plant-expressible promoter and any structural gene of interest to form recombinant DNA molecules. The elements are useful for enhancing the expression of a nearby plant-expressible gene. The patent describes that “enhancing the expression” of a gene means that the gene is activated only when the enhancer is present or gene expression is increased by the enhancer but it does not indicate how much expression has to be increased for a sequence to be considered as an enhancer.

The claims of the European and the Canadian patents cover sequences that are at least 50% homologous to the 16 bp OCS enhancer element. Also, the target plants for transformation with the recombinant molecules are limited to monocots. More information of the granted patents are presented in the table on the following page.