Positive selection using glucosamine-6-phosphate

Danisco A/S holds granted patents in the United States, Australia and New Zealand regarding the method for the positive selection of genetically transformed plant cells by glucosamine 6-phosphate.

Technology overview

To normal plant cells, glucosamine or its derivatives such as glucosamine 6-phosphate, is a nutrient when present in a low concentration, However, they become toxic when their concentration exceeds certain level.

Glucosamine 6-phosphate deaminase from Escherichia coli is an allosteric hexameric enzyme which catalyzes the reversible conversion of D-glucosamine-6-phosphate into D-fructose 6-phosphate and ammonium ion and is activated by N-acetyl-D-glucosamine 6-phosphate. By transforming a gene coding for the glucosamine 6-phosphate deaminase into plant cells, the transformed cells will acquire the capability of converting glucosamine-6-phosphate to fructose-6-phosphate and ammonium. In this way, the transformed plant cells can use glucosamine-6-phosphate at a high concentration as a source of both carbohydrate and nitrogen for their growth over the non-transformed cells.

Detailed patent information

Patent number Title, Independent Claims and Summary

Assignee

US 6444878

  • Earliest priority – 7 Feb 1997 (UK)
  • Filed – 23 Dec 1999
  • Granted – 03 Sep 2002
  • Expected expiry – 23 Dec 2019
Title – Method of plant selection using glucosamine-6-phosphate deaminase

Claim 1
A selection method for selecting genetically transformed plant cells from a population of plant cells, comprising:transforming a population of plant cells with an expressible nucleotide sequence having at least 75% identity to SEQ ID NO: 1 and which encodes an enzyme having glucosamine-6-phosphate deaminase activity that converts a component or a metabolic derivative thereof when present in a high concentration in a medium into a nutrient, thereby producing a population of genetically transformed and non-transformed cells;introducing said population of plant cells to a medium comprising said component or metabolic derivative thereof, wherein the component or the metabolic derivative thereof is present in said medium in a high concentration and is toxic to said non-transformed plant cells and is a source of both carbohydrate and nitrogen for the selectable, genetically transformed plant cells or if a portion of the component serves as a metabolic substrate and is metabolically converted to a derivatized substrate, then that derivatized substrate provides an allosteric effect on the gene product; and

culturing said plant cells thereby selecting at least a portion of said transformed plant cells over said non-transformed plant cells; and, wherein said enzyme having glucosamine-6-phosphate deaminase activity converts glucosamine-6-phosphate to fructose-6-phosphate.

Claim 11
A composition comprising a population of transformed and non-transformed plant cells, said transformed plant cells being transformed with an expressible nucleotide sequence having at least 75% identity to SEQ ID NO: 1 and which encodes an enzyme having glucosamine-6-phosphate deaminase activity which converts a component or a metabolic derivative thereof into a nutrient, and a medium comprising said component or metabolic derivative thereof, wherein the component or the metabolic derivative thereof is present in said medium in a high concentration and is toxic to said non-transformed plant cells; and, wherein said enzyme having glucosamine-6-phosphate deaminase activity converts glucosamine-6-phosphate to fructose-6-phosphate.
Claim 15
A construct for genetically transforming a non-transformed plant cell to produce a selectable genetically transformed plant cell, said construct comprising: a plant promoter operably linked to an expressible nucleotide sequence encoding a glucosamine-6-phosphate deaminase gene product and having at least 75% identity to SEQ ID NO: 1; and, wherein said glucosamine-6-phosphate deaminase gene product converts glucosamine-6-phosphate to fructose-6-phosphate.
Claim 19
A transgenic plant produced from a cell transformed with an expressible nucleotide sequence having at least 75% identity to SEQ ID NO: 1and encoding an enzyme having glucosamine-6-phosphate deaminase activity.
Claim 21
An E. coli strain selected from the group consisting of NCIMB 40852, NCIMB 40853, and NCIMB 40854.

Danisco A/S

AU 739067 B2

  • Earliest priority – 7 Feb 1997 (UK)
  • Filed – 05 Feb 1998
  • Granted – 04 Oct 2001
  • Expected expiry – 05 Feb 2018
Title – Selection method for transgenic plant

Claim 1

A selection method for selecting from a population of cells one or more selectable genetically transformed cells;
wherein the population of cells comprises selectable genetically transformed cells and possible non-transformed cells;
wherein each of the selectable genetically transformed cells comprises a first expressable nucleotide sequence and optionally a second expressable nucleotide sequence;
wherein a component or a metabolic derivative thereof when present in a low concentration in a medium is a nutrient for both the selectable genetically transformed cells and the non-transformed cells;
wherein the component or the metabolic derivative thereof when present in a high concentration in a medium is toxic to the non-transformed cells;
wherein the first nucleotide sequence codes for a gene product capable of converting the component or the metabolic derivative thereof when present in a high concentration in a medium to a nutrient for the selectable genetically transformed cells;
the method comprising the step of introducing the population of cells to a medium;
wherein the medium optionally comprises a high concentration of the component or the metabolic derivative thereof; and
either wherein the component or the metabolic derivative thereof is a source of both carbohydrate and nitrogen for the selectable genetically transformed cells;
or wherein if a portion of the component serves as a metabolic substrate and is metabolically converted to a derivatised substrate, then that derivatised substrate is capable of providing an allosteric effect on the gene product.

Claim 21
Use of glucosanmine-6-phosphate deaminase as a selection means for selecting a genetically transformed cell over a non-transformed cell.
Claim 22

Use of a gene coding for glucosamine-6-phosphate deaminase for providing a selection means for selecting a genetically transformed cell over a non-transformed cell.

Claim 23

Use of a gene coding for glucosamine-6-phosphate deaminase obtained from NCIMvB 40852 or NCIMB 40853 or NCIMB 40854 for providing a selection means for selecting a genetically transformed cell over a non-transformed cell.

Remarks

Related patent was also granted in New Zealand (NZ 336925). The European application (EP 970221 A1) was deemed to be withdrawn on 30 Dec 2005. Patent applications were also filed in Canada (CA 2280236), China (CN 1252097) and Japan (JP 2002514915).

Search stratagy

Search details
Date of search 30/05/2006
Database searched Patent Lens
Type of search Simple, stemming on
Collections searched AU-B, US-A, US-B, EP-B, WO
Search terms “Danisco” in applicant

“cell selection” in abstract

Results 12 hits
Comments Both US 6444878 and AU 739067 B2 were listed