Skip to main content
Article
Opposing Interactions between Homothorax and Lobe define the Ventral Eye Margin of Drosophila Eye
Developmental Biology
  • Amit Singh, University of Dayton
  • Meghana Tare, University of Dayton
  • Madhuri Kango-Singh, University of Dayton
  • Won-Seok Son, Korea Advanced Institute of Science and Technology
  • Kyung-Ok Cho, Korea Advanced Institute of Science and Technology
  • Kwang-Wook Choi, Baylor College of Medicine
Document Type
Article
Publication Date
11-1-2011
Abstract
Patterning in multi-cellular organisms involves progressive restriction of cell fates by generation of boundaries to divide an organ primordium into smaller fields. We have employed the Drosophila eye model to understand the genetic circuitry responsible for defining the boundary between the eye and the head cuticle on the ventral margin. The default state of the early eye is ventral and depends on the function of Lobe (L) and the Notch ligand Serrate (Ser). We identified homothorax (hth) as a strong enhancer of the Lmutant phenotype of loss of ventral eye. Hth is a MEIS class gene with a highly conserved Meis-Hth (MH) domain and a homeodomain (HD). Hth is known to bind Extradenticle (Exd) via its MH domain for its nuclear translocation. Loss-of-function ofhth, a negative regulator of eye, results in ectopic ventral eye enlargements. This phenotype is complementary to the L mutant phenotype of loss-of-ventral eye. However, if L and hth interact during ventral eye development remains unknown. Here we show that (i) L acts antagonistically to hth, (ii) Hth is upregulated in the L mutant background, and (iii) MH domain of Hth is required for its genetic interaction with L, while its homeodomain is not, (iv) in L mutant background ventral eye suppression function of Hth involves novel MH domain-dependent factor(s), and (v) nuclear localization of Exd is not sufficient to mediate the Hth function in the L mutant background. Further, Exd is not a critical rate-limiting factor for the Hth function. Thus, optimum levels of L and Hth are required to define the boundary between the developing eye and head cuticle on the ventral margin.
Inclusive pages
199–208
ISBN/ISSN
0012-1606
Comments

Permission documentation is on file.

Publisher
Elsevier
Peer Reviewed
Yes
Citation Information
Amit Singh, Meghana Tare, Madhuri Kango-Singh, Won-Seok Son, et al.. "Opposing Interactions between Homothorax and Lobe define the Ventral Eye Margin of Drosophila Eye" Developmental Biology Vol. 359 Iss. 2 (2011)
Available at: http://works.bepress.com/amit_singh/26/