Evidence for Notch-mediated lateral inhibition in organizing butterfly wing scales.

Here I present gene expression data that implicate a Notch-mediated lateral inhibition process in the spatial organization of butterfly wing scales. During early pupal development the receptor molecule Notch is expressed in a grid-like pattern in the wing epithelium, resulting in parallel rows of uniformly spaced cells with low Notch expression. Previous work has shown that these low-Notch cells express a homolog of the achaete-scute proneural transcription factors and develop into scales. All of these observations are consistent with the Drosophila model of Notch-mediated bristle determination and support the hypothesis that bristles and scales share an underlying patterning mechanism.