QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

This Article Summary Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Shyamala, B. V. Articles by Bhat, K. M. Search for Related Content PubMed PubMed Citation Articles by Shyamala, B. V. Articles by Bhat, K. M.

A positive role for Patched-Smoothened signaling in promoting cell proliferation during normal head development in Drosophila

Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322, USA

View larger version (69K): [in a new window]   Fig. 1. Ptc is required for head capsule morphogenesis. Wild-type adult normal head is shown in A, the head capsule formation defects in ptchdl/ptcIN108 pharate adults are shown in B (mild head deformation with a frontal median cleft and loss of antenna), C (moderate phenotype with unilateral loss of head case) and D (severely reduced head with tiny eyes attached to the thorax). (E) A ptcgal4/ptcIN108 individual. (F) The head capsule defect in the mitotic clones of ptcIN108/ptcIN108 (in ptcIN108/+ background).

View larger version (60K): [in a new window]   Fig. 2. The fate map of eye-antennal disc and its relationship to Ptc expression domain. (A,B) Fate map of the different regions of the disc contributing to various structures of the adult head. (C) A late 3rd instar larval eye-antennal disc stained with an antibody against Ptc. (D) Ptc expression domains in the eye-antennal disc.

View larger version (85K): [in a new window]   Fig. 3. The loss of Ptc activity affects the development of the eye-antennal disc. The discs were stained with Phalloidin and examined by confocal microscopy. (A,B) Control (ptcH84/CyO or ptchdl/CyO) and ptchdl/ptcH84 mutant discs, respectively, dissected from the late 3rd instar larval stages. (C,D) Control (ptcH84/CyO or ptchdl/CyO) and ptchdl/ptcH84 mutant discs, respectively, dissected from very late 3rd instar discs and cultured in vitro overnight (see Materials and Methods). The development of the discs in vitro appears to be equivalent to approximately 1-day old brown pupae.

View larger version (89K): [in a new window]   Fig. 4. Cell-proliferation is affected in the eye-antennal disc of ptc mutant individuals. (A-D) BrdU incorporation in wild-type and ptc mutant eye-antennal discs from late 3rd instar stages, stained with anti-BrdU. (A) Wild type. (B) A pair of eye-antennal discs from the same ptchdl/ptcH84 individual; the disc on the right shows reduced BrdU incorporation (the bilateral difference in the incorporation is consistent with the unilateral head capsule defect). (C) Another pair of ptchdl/ptcH84 eye-antennal discs; the disc on the right has very few BrdU-positive cells. (D) Domains of cells in a 3rd instar larval eye-antennal disc where Ptc expression is very strong. Note that there is a low level of Ptc expression in most of the cells in the eye-antennal disc. The loss of BrdU incorporation corresponds generally to the Ptc-expression domains. (E-G) Anti-Phosphohistone-3 (PH3) staining (red; green is Phalloidin staining) of the eye-antennal discs 1 hour after puparium formation. (E) Wild type, note that many cells are dividing. (F,G) ptchdl/ptcH84 discs, a few cells are undergoing mitosis.

View larger version (57K): [in a new window]   Fig. 5. Ptc-signaling during head morphogenesis. Pharate adults are shown. (A) Hs-hh individual. (B) The head capsule defect in smo/+ pharate adult with smo– mitotic clones. (C) babo32/Df (2R) NP1 individual. (D) ptcH84, +/+, babo32 individual. (E,F) ptcgal4/Df (2R) NP3; UAS-baboact individual, ventral and dorsal views. Note that the head capsule defect is completely rescued by the expression of activated Babo in the Ptc-domain from the ptcgal4 (see text). (G) ptchdl/ptcH84; UAS-baboact/69B-GAL4, the head capsule defect is also rescued by the expression of activated Babo using a disc-specific driver (see text). (H) The genetic epistatic relationship between hh, ptc, smo and babo during head development. This genetic pathway does not necessarily indicate a linear relationship between Ptc-Smo signaling and Babo signaling, as there are other possibilities that have not been ruled out (see text).