BIDIRECTIONAL TRANSCRIPTION FROM ACTIN PROMOTERS IN DICTYOSTELIUM

Numerous transformation vectors for Dictyostelium discoideum have been constructed by fusing actin 6 and 15 promoters to selectable markers such as G418 and hygromycin. Strand specific probing of RNAs from tran sformed cells demonstrates that cells containing these vectors accumul ate transcripts representing both strands of the vector. The evidence is consistent with bidirectional transcription initiating in the trunc ated actin promoter fragments. A larger fragment of the actin 15 promo ter largely eliminates this problem.