Document Type

Article

Publication Date

10-2010

Publication Source

Developmental Biology

Abstract

Axial patterning is crucial for organogenesis. During Drosophila eye development, dorso-ventral (DV) axis determination is the first lineage restriction event. The eye primordium begins with a default ventral fate, on which the dorsal eye fate is established by expression of the GATA-1 transcription factor pannier (pnr). Earlier, it was suggested that loss of pnr function induces enlargement in the dorsal eye due to ectopic equator formation. Interestingly, we found that in addition to regulating DV patterning, pnr suppresses the eye fate by downregulating the core retinal determination genes eyes absent (eya), sine oculis (so) and dacshund (dac) to define the dorsal eye margin. We found that pnr acts downstream of Ey and affect the retinal determination pathway by suppressing eya. Further analysis of the “eye suppression” function of pnr revealed that this function is likely mediated through suppression of the homeotic gene teashirt (tsh) and is independent of homothorax (hth), a negative regulator of eye. Pnr expression is restricted to the peripodial membrane on the dorsal eye margin, which gives rise to head structures around the eye, and pnr is not expressed in the eye disc proper that forms the retina. Thus, pnr has dual function, during early developmental stages pnr is involved in axial patterning whereas later it promotes the head specific fate. These studies will help in understanding the developmental regulation of boundary formation of the eye field on the dorsal eye margin.

Inclusive pages

258–271

ISBN/ISSN

0012-1606

Document Version

Postprint

Comments

The paper available for download here is the authors' accepted manuscript, published in final edited form in Dev Biol. 2010 October 15; 346(2): 258–271.

Publisher's disclaimer: The manuscript in this form had not yet undergone copy editing, typesetting, and review of the resulting proof. Please note that during the production process, errors may have been discovered that could affect the content, and all legal disclaimers that apply to the journal pertain.

Acknowledgment from the authors: "We thank Kwang-Wook Choi, J. Treisman, Y Henry Sun, Justin Kumar, Fernando Casares, H. McNeill, S. Campuzano, Nancy Fossett, and the Bloomington Stock Center for the Drosophila strains; U. Walldorf, Patrick Callaerts, K. Cho and the Developmental Studies Hybridoma Bank (DSHB) for the antibodies; and members of Singh and Kango-Singh lab for critical comments on the manuscript. We thank Shiranee Gunasekera for fly food and stock maintenance. Confocal microscopy was supported by Biology Department central core facility. SMO has been supported by the Fight for Sight Inc. Summer research fellowship and an award from the Szabo Endowment fund. MKS is supported by Knights Templar Eye Foundation Inc., and start-up support from University of Dayton. This work is supported by NIH grant (1R15 HD064557-01), start-up support from University of Dayton, and Ohio Cancer Research Associates seed grant to AS."

Publisher

Society for Developmental Biology

Volume

346

Issue

2

Peer Reviewed

yes

Keywords

Drosophila eye, Dorso-ventral eye patterning, pannier, GATA-1, retinal determination, homothorax, teashirt, Wg Signaling