Transgenic or recombinant non-human mammals and their uses in screening psychoactive medicines

Abstract

The invention concerns transgenic or recombinant non-human mammals, wherein the expression of the gene coding for a microtubule associated protein (MAP) is modified (STOP gene) (inactivation or overexpression) and their uses in screening medicines useful in schizophrenia and schizo-affective disorders, with anxious, paranoiac or depressive component.

1 . A recombinant non-human mammal carrying at least one modified allele of the gene encoding a STOP protein.  
     
     
         2 . The recombinant non-human mammal as claimed in  claim 1 , characterized in that said modified allele is obtained from a construct comprising a nucleic acid sequence derived from the same mammal or from a mammal which is different from that into which said construct is inserted, which construct is selected from the group consisting of constructs containing a sequence encoding a STOP protein which is antisense, constructs comprising the region of the STOP promoter in combination with a reporter gene or with the STOP coding region, constructs comprising at least one portion of the STOP gene including at least one modification, and constructs comprising at least one portion of the STOP gene functionally linked to a promoter and, optionally, to other regulatory sequences required for expression in the host animal.  
     
     
         3 . The recombinant non-human mammal as claimed in  claim 1  or  claim 2 , characterized in that said constructs are selected from the following constructs: constructs which include a fragment of the genomic sequence encoding a STOP protein included between the initiation codon and the STOP codon, constructs which do not comprise the region between positions  4118  and  5131  of the genomic sequence encoding a STOP protein, and constructs comprising 4.1 kb of the STOP gene, the gene encoding β-galactosidase, placed under the control of the endogenous STOP promoter, a neomycin resistance gene under the control of the PGK promoter, 1.57 kb of sequence of the STOP gene and, finally, the thymidine kinase gene under the control of PGK promoter.  
     
     
         4 . The use of a recombinant non-human mammal as claimed in any one of  claims 1  to  3 , for selecting or screening psychoactive products.  
     
     
         5 . A nucleic acid molecule, characterized in that it comprises the sequence of a modified allele of the gene encoding a STOP protein as defined in any one of  claims 1  to  3 , excluding the sequences corresponding to the GENBANK accession numbers AJ002556 and Y16032.  
     
     
         6 . A probe or a primer for screening recombinant ES clones or recombinant animals, characterized in that it is selected from the group consisting of the sequences SEQ ID Nos. 3 to 6.  
     
     
         7 . A method for screening and selecting molecules of use in the treatment of schizophrenia and schizoaffective disorders with a component of anxiety, paranoia or depression, which method is characterized in that it comprises at least the following steps: 
 bringing at least one substance to be screened into contact, in vitro, with a biological sample consisting of an extract of cells or organ slices, preferably of neurons or brains, obtained from at least one recombinant non-human mammal carrying at least one modified allele of the gene encoding a STOP protein as claimed in any one of  claims 1  to  3 ,    measuring the action of said substance to be screened on said cells or organ slices, and    comparing the values obtained with those of the cells or of the organ slices of a biological sample obtained from a non-human mammal of the same type, carrying two wild-type alleles of the gene encoding a STOP protein.    
     
     
         8 . The method as claimed in  claim 7 , characterized in that said measurement is carried out using a protein-protein binding assay.  
     
     
         9 . The method as claimed in  claim 7 , characterized in that said measurement is carried out by detection of the variation in strength of an electrical signal.  
     
     
         10 . A vector for homologous recombination of a gene encoding a STOP protein, characterized in that it comprises a nucleotide sequence of a modified STOP gene encoding an inactivated STOP protein, preferably truncated in at least one of the exons, in particular exon  1 .  
     
     
         11 . The use of the substances selected using the screening method as claimed in any one of  claims 7  to  9 , for preparing a medicinal product of use in the treatment of schizophrenia and schizoaffective disorders with a component of anxiety, paranoia or depression.  
     
     
         12 . The use of a primer or of a probe as claimed in  claim 6 , for screening recombinant ES clones or recombinant animals.