Rhomboid in-situ of a UAS-inx7-expressing pupal wing.
The pupal wing shown has the genotype 2GM1GAL4 /+; UAS-inx73U7X8 /+. Dark-staining regions indicate where the rhomboid transcript is detected at high levels (white arrows). In wild type wings these areas correspond to cell populations that adopt the vein cell-fate. The image reveals that expression of inx7 in the intervein domains of the developing wings increases the size of cells, or number of cells, adopting the vein cell-fate. The Notch pathway has an important role in coordinating the adoption of cell-fates, including vein-fate determination. inx2 overexpression and mutation has previously been reported to alter paracrine signaling pathways (wingless, hedgehog, Notch) during embryonic gut development ( Lechner et al. 2007, “Cross regulation of intercellular gap junction communication and paracrine signaling pathways during organogenesis in Drosophila”) and it is possible that UAS-inx7 exerts a similar disruptive influence on paracrine signaling pathways during wing development, leading to the wing phenotype above.