Cross-Species Patent Coverage

As discussed in Chapter 2 of this landscape, rice has significant homology and synteny with other plant species. This leads to the possibility that composition of matter claims for rice sequences and related sequences (related by a specified percent identity or by hybridization) will encompass similar sequences in other plants. We refer to this as “cross-coverage”.
For example, a claim that reads:

An isolated nucleic acid sequence that has at least 80% sequence identity to SEQ ID NO:10.

may “literally” cover more than one species if there are sequences from more than one species that fall within the 80% sequence identity range.
In the U.S., there is a presumption of validity for patent claims, but there are a number of other factors that may actually limit the scope of claims that at first glance appear to literally cover other species. Some of these factors include:

  • The specification may contain language that limits the scope of the claim. Claims are interpreted in light of the specification. For example, if the specification describes the related sequences as being maize sequences, then sequences from other plants, such as rice, may not fall under the scope of the claims, even if they are more than 80% identical.
  • The legal interpretation of the claim may limit the scope. There may have been court cases that have clarified or defined how certain types of patent claims are interpreted.

A detailed analysis is necessary to determine if a patent claim to a sequence covers more than one species.

There are a number of ways that the claim language itself may limit the number of species covered. For example:

  • The species may be recited in the claim. For example, the claim might read:
An isolated nucleic acid sequence that has at least 80% sequence identity to SEQ ID NO:10, wherein the isolated nucleic acid sequence is from maize.

Because this claim specifies maize, it would likely not cover rice.

  • The claim may be limited to monocots or dicots.
An isolated nucleic acid sequence that has at least 80% sequence identity to SEQ ID NO:10, wherein the isolated nucleic acid sequence encodes a polypeptide of a monocot.

In this case, a polypeptide that was more than 80% identical that encoded a dicot polypeptide would likely not fall under the scope of the claim.

  • The claim may specify a function for the sequence. Functional language limits the claim to sequences that have a particular function.
An isolated nucleic acid sequence that has at least 80% sequence identity to SEQ ID NO:10, wherein the isolated nucleic acid sequence encodes a soluble starch synthase.

With this claim, if there were a sequence that was more than 80% identical that encodes an insoluble starch synthase, it would probably not fall under the scope of the claim.