Abstract: The present invention concerns the use of a nucleic acid fragment comprising a portion of at least 100 contigous nucleotide bases which portion has a sequence the same as, or homologous to a portion of corresponding length of the sequence as set out in SEQ ID NO:1 starting at nucleotide approximately 1 and ending at nucleotide approximately 16879 or the same as, or homologous to a portion of the corresponding length of the sequence complementary to said SEQ ID NO: 1 within the specified positions, for improving the persistence of transfected cells expressing one or more gene(s) of interest operably linked to said acid nucleic fragment. The invention also relates to an expression cassette for the expression of one or more gene(s) of interest which expression is controlled by one or more control sequence(s) and a nucleic acid fragment as defined above.

Abstract: The present invention provides a reagent for the detection or monitoring of a Toxoplasma gondii infection, which includes as a reactive substance a truncated Toxoplasma gondii P30 protein in which all of the hydrophobic C-terminal region of the native protein starting with the amino acid positioned after the amino acid 299 (SEQ ID NO: 1) has been deleted and all of the region of the native protein having the sequence starting with amino acid 31 and ending with the amino acid 299 (SEQ ID NO: 1) is contained.

Abstract: The present invention provides a reagent for the detection or monitoring of a Toxoplasma gondii infection, which includes as a reactive substance a truncated Toxoplasma gondii P30 protein in which all of the hydrophobic C-terminal region of the native protein starting with the amino acid positioned after the amino acid 299 (SEQ ID NO: 1) has been deleted and all of the region of the native protein having the sequence starting with amino acid 31 and ending with the amino acid 299 (SEQ ID NO: 1) is contained. The present invention further describes methods of screening for anti-Toxoplasma antibodies in a biological sample.

Abstract: The present invention relates to a system for producing a protein of interest in a host cell comprising the combined use of two expression cassettes, one of which is for expressing a useful DNA fragment controlled by a thiamine-regulable promoter region, while the other is for expression an activator gene. The present invention also concerns expression cassettes comprising a useful DNA fragment controlled by a promoter region derived from the Schizosaccharomyces pombe pho-4 gene, as well as the vectors and cells comprising such an expression cassette. A novel method for the production of a useful protein is also provided.