Open Close
Joshi, M., Buchanan, K.T., Shroff, S., Orenic, T.V. (2006). Delta and Hairy establish a periodic prepattern that positions sensory bristles in Drosophila legs.  Dev. Biol. 293(1): 64--76.
FlyBase ID
Publication Type
Research paper

In vertebrates and invertebrates, spatially defined proneural gene expression is an early and essential event in neuronal patterning. In this study, we investigate the mechanisms involved in establishing proneural gene expression in the primordia of a group of small mechanosensory bristles (microchaetae), which on the legs of the Drosophila adult are arranged in a series of longitudinal rows along the leg circumference. In prepupal legs, the proneural gene achaete (ac) is expressed in longitudinal stripes, which comprise the leg microchaete primordia. We have previously shown that periodic ac expression is partially established by the prepattern gene, hairy, which represses ac expression in four of eight interstripe domains. Here, we identify Delta (Dl), which encodes a Notch (N) ligand, as a second leg prepattern gene. We show that Hairy and Dl function concertedly and nonredundantly to define periodic ac expression. We also explore the regulation of periodic hairy expression. In prior studies, we have found that expression of two hairy stripes along the D/V axis is induced in response to the Hedgehog (Hh), Decapentaplegic (Dpp) and Wingless (Wg) morphogens. Here, we show that expression of two other hairy stripes along the orthogonal A/P axis is established through a distinct mechanism which involves uniform activation combined with repressive influences from Dpp and Wg. Our findings allow us to formulate a general model for generation of periodic pattern in the adult leg. This process involves broad and late activation of ac expression combined with refinement in response to a prepattern of repression, established by Hairy and Dl, which unfolds progressively during larval and early prepupal stages.

PubMed ID
PubMed Central ID
Associated Information
Associated Files
Other Information
Secondary IDs
    Language of Publication
    Additional Languages of Abstract
    Parent Publication
    Publication Type
    Dev. Biol.
    Developmental Biology
    Publication Year
    Data From Reference