Methods for identifying genes and promoters of interest using the

1. A method for identifying a gene associated with a detectable phenotype in a fungus, comprising:

(a) transforming the fungus with a polynucleotide comprising a marker gene which would otherwise be transcriptionally active in the fungus but which has been inactivated by the insertion of a defective Impala transposon, said marker gene comprising, in the direction of transcription, a promoter regulatory sequence of the niaD gene from Aspergillus nidulans which is more than 0.4 kb long and which is functionally linked to the coding sequence of said marker gene;

(b) mobilizing the defective Impala transposon using a transposase, the expression of which is controlled, under conditions which allow the excision of the Impala transposon, and further controlling expression of the transposase so as to permit reinsertion and stabilization of the Impala transposon in the genome of the fungus;

(c) selecting at least one insertion mutant with said detectable phenotype; and

(d) isolating the gene into which, or close to which, the Impala transposon has inserted in the insertion mutant selected in (c).

2. The method of claim 1 , wherein the marker gene encodes an enzyme that is active in the fungus.

3. The method of claim 2 , wherein the marker gene encodes a nitrate reductase or a nitrilase.

4. The method of claim 3 , wherein the marker gene is a nitrate reductase gene from Aspergillus nidulans.

5. The method of claim 1 , 2 , 3 , or 4 , wherein Impala transposon is integrated into the promoter regulatory sequence.

6. The method of claim 5 , wherein the Impala transposon carries an additional marker gene.

7. A method for identifying a gene associated with a detectable phenotype of interest in Magnaporthe grisca , comprising:

(a) transforming Magnaporthe grisea fungi which lack the detectable phenotype of interest with a polynucleotide comprising a selectable marker gene, the coding sequence of which is functionally linked to a promoter regulatory sequence which is functional in Magnaporthe grisea , wherein an inserted Impala transposon suppresses expression of the marker gene, to produce transformants;

(b) providing conditions which allow the transposition of the Impala transposon in the transformants;

(c) screening the transformants for the expression of the marker gene in order to select insertion mutants resulting from the transposition and re-insertion of the Impala transposon;

(d) selecting at least one insertion mutant with said detectable phenotype of interest; and

(e) isolating the gene into which, or close to which, the Impala transposon has inserted in the insertion mutant selected in (d).

8. The method of claim 7 , wherein the conditions which allow transpositions are provided include introducing a transposase.

9. A method for identifying a gene associated with a detectable phenotype of interest in a fungus, comprising:

(a) transforming fungi which lack the detectable phenotype of interest with a polynucleotide comprising a selectable marker gene, the coding sequence of which is functionally linked to a promoter regulatory sequence which is functional in Magnaporthe grisca , wherein an inserted Impala transposon suppresses expression of the marker gene, to produce transformants;

(b) providing a transposase to allow the transposition of the Impala transposon in the transformants;

(c) screening the transformants for the expression of the marker gene in order to select insertion mutants resulting from the transposition and re-insertion of the Impala transposon;

(d) selecting at least one insertion mutant with said detectable phenotype of interest; and

(e) isolating the gene into which, or close to which, the Impala transposon has inserted in the insertion mutant selected in (d);

wherein the marker gene is selected from the group consisting of: (i) a reporter gene selected from the group consisting of glucuronidase and green fluorescent protein: (ii) a gene that confers tolerance to an antibiotic selected from the group consisting of hygromycin, phleomycin and sulfonylurea; and (iii) a gene that confers tolerance to a bialaphos herbicide.

10. The method of claim 9 , wherein the marker gene is a reporter gene selected from the group consisting of glucuronidase and green fluorescent protein.

11. The method of claim 9 , wherein the marker gene is a gene that confers tolerance to an antibiotic selected from the group consisting of hygromycin, phleomycin, and sulfonylurea.

12. The method of claim 9 , wherein the marker gene is the gene that confers tolerance to the herbicide bialaphos.

13. The method of claim 9 , wherein the Impala transposon is integrated into the promoter regulatory sequence.

14. The method of claim 9 , wherein the Impala transposon is integrated into an intron of the marker gene.

15. A method for identifying a promoter of interest in a fungus, comprising:

(a) transforming fungi with a polynucleotide comprising a first marker gene, said first marker gene comprising a promoter regulatory sequence which is functional in Magnaporthe grisca functionally linked to the coding sequence of said first marker gene and an Impala transposon comprising a second marker gene, wherein expression of said first marker gene is inactivated by the insertion of the Impala transposon and the second marker gene lacks an operably linked promoter sequence, to produce transformants;

(b) providing conditions which allow the transposition of the Impala transposon in the transformants;

(c) screening the transformants for the expression of the first marker select insertion mutants resulting from the transposition of the Impala element;

(d) selecting at least one insertion mutant which expresses the second marker gene; and

(e) isolating the promoter into which, or close to which, the Impala transposon has inserted in the insertion mutant selected in (d) to result in expression of the second marker gene.