Autoregulatory and gap gene response elements of the even‐skipped promoter of Drosophila.

The pair‐rule gene even‐skipped (eve) plays a key role in the regulatory hierarchy governing segmentation in Drosophila. Here we describe the use of P‐transformation and eve promoter fusions to identify cis elements that regulate the periodic seven‐stripe eve pattern. A distal region of the eve promoter, located between −5.9 and −5.2 kb, controls autoregulation. Sequences from this region will induce striped expression of a heterologous hsp70 basal promoter in the presence, but not absence, of endogenous eve+ products. Autoregulatory activity was localized to a 200‐bp region of the distal eve promoter. We also provide evidence that individual eve expression stripes are regulated by separate cis sequences. eve promoter sequences located between −4.7 and −3 kb upstream of the transcription start site are important for the initiation of stripe 3, whereas sequences between −1.7 and −0.4 kb are needed for stripes 2 and 7. It is possible that these latter regions are directly regulated by the products of gap genes.