Extracellular Signals Responsible for Spatially Regulated Proliferation in the Differentiating Drosophila Eye

Abstract

Evidence of a role for T-box genes in the evolution of limb morphogenesis and the specification of forelimb/hindlimb identity. Mech. Dev. 56, 93-101.

Gcm protein degradation suppresses proliferation of glial progenitors

“…4F). During Drosophila retina development, Cyc E protein peaks in G1-arrested precluster cells that lack Cyc B, and Cyc E diminishes in cells that express Cyc B and undergo an extra round of cell division (28). Our result echoes the complementary expression of Cyc B and Cyc E in cell cycle progression in retina development.…”

Non-cell autonomous control of apoptosis by ligand-independent Hedgehog signaling in Drosophila

“…Hh activity produces several signaling molecules in the MF that activate Dpp, EGFR and N pathways for regulation of proliferation and differentiation in the eye disc. 8,11,13 Although we cannot exclude a role of EGFR and Dpp signaling, five lines of evidence implicate the N pathway for control of non-cell autonomous survival. First, the suppression of GMR-hid in cos2 mosaics is abrogated by reduced N pathway activity (e.g., heterozygosity for N or the ligands Dl and Serrate (Ser)) (Figures 5a-d).…”

“…[10][11][12][13] Hh and Dpp also induce the expression of the Notch (N) ligand Delta, which, in turn, induces a round of mitosis (second mitotic wave) in cells just posterior to the MF. 11,14 Thus, the Hh pathway is needed for MF progression ( Figure 1h) and coordinates the transition from proliferation to differentiation, making it a critical target for homeostasis.…”

Signalling molecules, growth regulators and cell cycle control in Drosophila

“…While Notch imposes a cell cycle arrest in G 1 by inhibiting the activity of the E2F transcription factor in the wing, Notch acts as a positive regulator of E2F in the developing eye primordium of Drosophila. [24][25][26] In the Drosophila eye, retinal development exemplifies patterned cell proliferation. A wave of differentiation, known as the morphogenetic furrow (MF), spreads progressively across the eye primordium (reviewed in refs.…”

“…Notch exerts its function by positively regulating E2F activity and cyclin A expression, two effectors that regulate G 1 -S progression. 24,25 …”