In vivo system for testing slice modulators, useful e.g. for diagnosis, comprises cellular system containing spliceable nucleic acid that generates detectable signal when spliced

Test system (A) comprising at least one cellular in vivo system containing at least one spliceable nucleic acid (I), containing at least one intron, which is spliced and the mRNA translated to provide a detectable signal, in presence of at least one compound of interest (II), and optionally other auxiliaries, is new. Independent claims are also included for the following: (1) preparing (A); (2) identifying substances (B) that modulate (inhibit or activate) slice processes; and (3) diagnosing diseases by incubating (I), (II) and optionally auxiliaries in an in vivo cellular system and detecting splicing products. Die vorliegende Erfindung betrifft ein in vivo-Testsystem enthaltend: DOLLAR A (a) mindestens ein zelluläres in vivo-System enthaltend mindestens eine spleißfähige Nukleinsäure, welche mindestens ein Intron enthält, DOLLAR A (b) wobei die Nukleinsäure in (a) gespleißt und die mRNA translatiert wird DOLLAR A (c) und ein detektierbares Signal induziert DOLLAR A (d) in Gegenwart mindestens einer interessierenden Substanz DOLLAR A (e) ggf. weitere Hilfsmittel