The University of Georgia Research Foundation patent family
University of Georgia Research Foundation, Inc. has a granted patent in the United States on methods and materials for selecting transgenic cells based on arabitol or ribitol as positive selectable markers. Patent application was also filed in Australia.
The invention relates to isolated polynucleotide molecules coding for a protein possessing arabitol/ribitol dehydrogenase enzymatic activity and a protein possessing arabitol/ribitol kinase enzymatic activity. It also relates to a positive selection system that involves conferring to transformed cells (includes protoplasts, as well as cells of plants, animals and microorganisms) the ability to metabolize arabitol, ribitol and/or mannitol and selecting the transformed cells.
D-arabitol and ribitol are two of the four possible pentitols (five-carbon sugar alcohol, C5H12O5) formed by the reduction of ribose. In 2001, LaFayette and Parrott reported that E. coli strains B and K-12 cannot metabolize these pentitols. However, E. coli strain C originally isolated in the Lister Institute, London, in 1920 (NCTC 1983) can metabolize both D-arabitol and ribitol and thus grow on these pentitols when they are the sole carbon source. This ability is due to the presence of two genes coding for arabitol deydrogenase and ribitol dehydrogenase that convert arabitol and ribitol into xylulose and ribulose, respectively.
Plants are not able to metabolize arabitol and ribitol. The positive selection strategy in this aspect is to engineer plant cells by introducing an arabitol or ribitol dehydrogenase gene so that the transformed cells can utilise arabitol or ribitol as carbon source. For example, when a gene coding for a bacterial arabitol dehydrogenase is transferred into and expressed in a plant cell, the cell will be able to grow in a medium containing D-arabitol by converting arabitol into the plant-metabolizable xylulose, whereas an untransformed plant cell will not proliferate.
Specific patent information
|Patent/Application Number||Title, Independent Claims and Summary||Assignee|
|US 7005561 B2
||Title – Arabitol or ribitol as positive selectable markers
University of Georgia Research Foundation
|The related patent application in Australia (AU 200140117) has lapsed. A PCT application was also filed (WO 2001/66779).|
|Date of search||31/05/2006|
|Database searched||Patent Lens|
|Type of search||Simple, stemming on|
|Collections searched||AU-B, US-A, US-B, EP-B, WO|
|Search terms||“Positive AND selection AND transformation AND cell” in abstract|
|Comments||This search results in patents from several patent families that related to the positive selection topic:
1. the Syngenta family represented by WO 1993/05163
2. the “University of Georgia Research Foundation, Inc.” family represented by US 7005561
titled “Arabitol or ribitol as positive selectable markers”.