Disperse versus Compact Elements for the Regulation ofruntStripes inDrosophila

Abstract

AbstractThe segmented body pattern of theDrosophilaembryo is established through a hierarchical network of interacting genes. At each successive step in this pathway, transcriptional regulation is used to convert coarse positional information into finer patterns of gene expression. Central to this process are thecis-regulatory regions that drive the dynamic spatial expression of the different segmentation genes. Here we describe thecis-regulatory region of theruntgene. As found for both other primary pair-rule genes,hairyandeven-skipped,there are stripe-specific elements which mediate the initial regulation ofruntstripes by gap genes. We did not find autoregulatory elements as described foreven-skippedandfushi tarazu.The regulation ofruntby other pair-rule genes is mediated by a large region, extending over 5 kb upstream and downstream of the transcription start site. This “disperse” element cannot be subdivided into functionally independent subelements or minimal elements. Such disperse elements mediating pair-rule gene interactions may have escaped detection in other segmentation genes and may involve molecular mechanisms different from those mediating regulation by gap genes