Summary of patents on basic co-integrated vectors and methods

Max-Planck Society and Monsanto Company have both been granted basic patents on co-integrated vectors.

A co-integrated plasmid is the product of homologous recombination through a single crossover between a small plasmid of bacterial origin and an Agrobacterium Ti plasmid. In the patents filed by both entities, the resulting co-integrated plasmid or hybrid Ti plasmid contains at least:

  • a gene of interest between the left and right T-DNA border sequences, and
  • vir region, which allows the transfer of the gene of interest located between the two border sequences into the plant genome.

Both entities claim two plasmids involved in the assembly of a co-integrated plasmid:

  • a vector molecule containing a gene of interest to be transferred into a plant, called an intermediate cloning vector by Max-Plank and a first plasmid by Monsanto, and
  • a Ti plasmid containing the vir region and free of tumor-inducing genes, which is called an acceptor Ti plasmid by Max-Plank and a Ti plasmid by Monsanto.

In addition, they both claim a homologous region present in both plasmid types through which the recombination of the plasmids takes place to form a co-integrated vector. The main difference lies in the source of the homologous DNA sequence:

  • Max-Planck claims a homologous region derived from a small vector molecule of bacterial origin different from Agrobacterium.
  • Monsanto claims a homologous region derived from the external and attached left side to the left T-DNA border of Agrobacterium Ti plasmid, called left inside homology (LIH) region.

In conclusion

  • Claims in both patents require the use of a co-integrated plasmid with a homologous region derived either
    1. from a vector molecule, i.e. E. coli-derived vector, or
    2. from a LIH region of a Ti-plasmid.

Neither Max-Planck nor Monsanto has a patent in the United States. Until 2001, the United States did not publish patent applications and the application process is secret. Many rumors abound about possible interferences in the United States between Max-Planck and Monsanto. An interference is a procedure in which the inventor who is earliest-in-time is determined. That inventor is then awarded the patent. The interference process can be extremely lengthy. Thus, there may yet be a patent issuing in the United States.