Control of gene expression in eukaryotes

Abstract

A chemically inducible gene expression system is described. A chimeric gene having a first sequence comprising a promoter and a regulator polypeptide is linked with a second sequence comprising a promoter and a coding or non-coding sequence. Expression of the target gene of the second sequence is controlled by the regulator polypeptide which is acted upon by an inducer. The inducer is a chemical compound, such as OHP, which acts upon the OHP responsive regulator polypeptide, which can be obtained from Rhodococcus sp. V49. Various domain regions and complementary response elements are also described.

1 . A chimeric gene comprising a first nucleotide sequence comprising a 5′ regulatory region operably linked to a nucleic acid sequence which encodes a regulator polypeptide and an untranslated 3′ termination sequence, and a second nucleotide sequence comprising a 5′ regulatory region operably linked to a nucleic acid sequence which is a coding or non-coding sequence, the expression of said nucleic acid sequence of said second nucleotide sequence being controlled by said regulator polypeptide of said first nucleotide sequence using an inducer, said inducer thereby causing modulation of expression of said nucleic acid sequence of said second nucleotide sequence, and said nucleotide sequence of said regulator polypeptide and/or said 5′ regulatory region or parts thereof of said second nucleotide sequence being isolated from a prokaryote source.  
     
     
         2 . A chimeric gene according to  claim 1 , wherein one or more of said 5′ regulatory regulatory regions each comprises a promoter which allows expression in eukaryote cells and/or tissues.  
     
     
         3 . A chimeric gene according to  claim 1  or  2 , wherein the promoter of said 5′ regulatory region operably linked to said nucleic acid encoding said regulator polypeptide is a constitutive, developmentally regulated, tissue-specific, cell-specific or cell compartment-specific promoter.  
     
     
         4 . A chimeric gene according to  claim 3 , wherein said constitutive promoter is the CaMV 35S or CaMV 19S promoter.  
     
     
         5 . A chimeric gene according to  claim 3 , wherein said tissue-specific promoter is the patatin promoter or the petE promoter.  
     
     
         6 . A chimeric gene according to  claim 3 , wherein said cell compartment promoter is a chloroplast gene promoter or a mitochondrial gene promoter.  
     
     
         7 - 37 . (Canceled)  
     
     
         38 . A method of controlling eukaryotic gene expression comprising introducing into a eukaryotic cell with an inducible gene expression system, said inducible gene expression system comprising a first nucleotide sequence comprising a 5′ regulatory region operably linked to a nucleic acid sequence which encodes a regulator polypeptide and an untranslated 3′ termination sequence, and a second nucleotide sequence comprising a 5′ regulatory region operably linked to a nucleic acid sequence which is a coding or non-coding sequence, the expression of said nucleic acid sequence of said second nucleotide sequence being controlled by the regulator polypeptide of the first nucleotide sequence using an inducer, said inducer thereby causing modulation of expression of said nucleic acid sequence of said second nucleotide sequence, and said nucleotide sequence of said regulator polypeptide and/or said 5′ regulatory region, or parts thereof, of said second nucleotide sequence being isolated from a prokaryote source.  
     
     
         39 . A method according to  claim 38 , wherein said inducible gene expression system is a chemically inducible gene expression system.  
     
     
         40 . A method according to  claim 38  or  39 , wherein said coding sequence is homologous or heterologous in origin with respect to the eukaryote being transformed.  
     
     
         41 . A method according to  claim 38  or  39 , wherein expression of said nucleic acid sequence of said second nucleotide sequence, said second nucleotide sequence being a target gene, is increased or decreased, whether from a basal or medial level respectively, or completely repressed or activated.  
     
     
         42 . A method according to claims  38  or  39 , wherein an increase in target gene expression levels is caused by the addition or presence of said inducer.  
     
     
         43 - 58 . (Canceled)  
     
     
         59 . Plant tissue transformed in accordance with the method of claims  38 .  
     
     
         60 - 61 . (Canceled)