COPY-DEPENDENT AND POSITION-INDEPENDENT EXPRESSION OF RAT ALDOLASE A GENE

In order to understand the molecular mechanisms of the temporal and sp atial differences of gene expression in higher organisms, rat aldolase A gene carrying two distinct promoters was introduced into fertilized eggs and the resulting transgenic mice were analyzed, The transgene e xpression is tissue-specific and is developmentally regulated, In addi tion, the expression is regulated in a copy-dependent manner irrespect ive of where the transgene is integrated, suggesting that a mechanism excluding the effect of the integration site exists within the transge ne itself, To explore the conformational change of this gene in the ge nome, the DNase I hypersensitive sites of the gene were examined, Thre e sites (DHS-1, 2, and 3) were identified upstream and downstream of t he gene and these sites were retained in the transgene as well as in t he gene observed endogenously.