The domineering non-autonomy of frizzled and Van Gogh clones in the Drosophila wing is a consequence of a disruption in local signaling

The frizzled (fz) gene is required for the development of distally pointing hairs on the Drosophila wing. It has been suggested that fz is needed for the propagation of a signal along the proximal distal axis of the wing. The directional domineering non-autonomy of fz clones could be a consequence o f a failure in the propagation of this signal. We have tested this hypothes is in two ways. Tn one set of experiments we used the domineering non-auton omy of fz: and Vang Gogh (Vang) clones to assess the direction of planar po larity signaling in the wing. prickle (pk) mutations alter wing hail polari ty in a cell autonomous way, so pk cannot be altering a global polarity sig nal. However, we found that pk mutations altered the direction of the domin eering non-autonomy of fz and Vang clones, arguing that this domineering no n-autonomy is not due to an alteration in a global signal. In a second seri es of experiments we ablated cells in the pupal wing. We found that a lack of cells that could be propagating a long-range signal did not alter hair p olarity. We suggest that fz and Vang clones result in altered levels of a l ocally acting signal and the domineering non-autonomy results from wild-typ e cells responding to this abnormal signal. (C) 2000 Elsevier Science Irela nd Ltd. All rights reserved.