defective proventriculus (dve), a new member of DV patterning in the eye. Oorvashi Roy G. Puli¹, Takeshi Yorimitsu³, Hideki Nakagoshi³, Amit Singh^1,2,4. 1) Department of Biology, University of Dayton, 300 College Park Drive, Dayton, OH; 2) Premedical Program, University of Dayton, 300 College Park Drive, Dayton, OH; 3) School of Natural Science and Technology, Okayama University, 3-1-1 Tsushima-naka, Kita-ku, Okayama 700-8530, Japan; 4) Center for Tissue Regeneration and Engineering at Dayton (TREND), University of Dayton, Dayton, OH.

   Axial patterning is crucial to eye development. During eye development, Dorso-ventral (DV) axis determination is the first lineage restriction event. The early eye primordium begins with the default ventral fate on which the dorsal eye fate is established by expression of a GATA-1 transcription factor, pannier (pnr). There is a need to identify new components to understand the mechanism of DV patterning. We have identified defective proventriculus (dve) as a new dorsal eye gene. Loss-of-function (LOF) of dve in the eye results in dorsal eye enlargements, ectopic eyes, antennal duplications and loss of ocelli. Gain-of-function (GOF) of dve suppresses the eye fate by regulating the RD genes. dve misexpression does not affect Ey but downregulates the downstream targets eyesabsent(eya), sine oculis (so) and dachshund (dac), suggesting that dve acts downstream of ey and is involved in blocking retinal differentiation to promote the dorsal head fate. Using genetic epistasis we found that dve acts downstream of pnr and upstream of wingless (wg). We found that dve is involved in regulating the Wg morphogen gradient in the eye. Here we present dve as a novel dorsal gene required in the dorsal eye during development.