AT-RICH UPSTREAM SEQUENCE ELEMENTS REGULATE SPORE GERMINATION-SPECIFIC EXPRESSION OF THE DICTYOSTELIUM-DISCOIDEUM CELA GENE

Two members of a family of spore germination-specific cDNAs, celA and celB, are expressed coordinately, exclusively during spore germination . In the present study the regulatory sequence elements responsible fo r celA germination-specific expression have been identified. The very AT-rich 81 bp sequence between -664 and -584 upstream of the translati on initiation site was required for proper temporal transcription of t he celA gene. This sequence is comprised of two cis elements, each of which was active by itself in allowing celA expression. Electrophoreti c mobility shift assays showed that a factor(s) in an extract prepared from germinating spores bound to the celA regulatory region. One of t he three complexes formed was specific for the germinating spore extra ct, The results are consistent with the notion that the factor(s) that binds to this regulatory region is involved in expression of celA.