TheDrosophilacytokine receptor Domeless controls border cell migration and epithelial polarization during oogenesis

Abstract

In mammals, the JAK/STAT (Janus Kinase/Signal Transducer and Activator of Transcription) signaling pathway is activated in response to cytokines and growth factors to control blood cell development, proliferation and cell determination. In Drosophila, a conserved JAK/STAT signaling pathway controls segmentation in embryos, as well as blood cell development and other processes in larvae and adults. During embryogenesis, transduction of the Unpaired [Upd; also known as Outstretched (Os)] ligand through the JAK/STAT pathway requires Domeless, a putative membrane protein with distant homology to vertebrate type I cytokine receptors. We have isolated domeless(dome) in a screen to identify genes essential in epithelial morphogenesis during oogenesis. The level of dome activity is critical for proper border cell migration and is controlled in part through a negative feedback loop. In addition to its essential role in border cells, we show that dome is required in the germarium for the polarization of follicle cells during encapsulation of germline cells. In this process,dome controls the expression of the apical determinant Crumbs. In contrast to the ligand Upd, whose expression is limited to a pair of polar cells at both ends of the egg chamber, dome is expressed in all germline and follicle cells. However, the Dome protein is specifically localized at apicolateral membranes and undergoes ligand-dependent internalization in the follicle cells. dome mutations interact genetically with JAK/STAT pathway genes in border cell migration and abolish the nuclear translocation of Stat92E in vivo. We also show that domefunctions downstream of upd and that both the extracellular and intracellular domains of Dome are required for JAK/STAT signaling. Altogether,our data indicate that Dome is an essential receptor molecule for Upd and JAK/STAT signaling during oogenesis.

Cytokine signaling through the JAK/STAT pathway is required for long-term memory in Drosophila

“…S1). To achieve better resolution, we next examined the expression pattern of Upd, Stat92E, and Dome by using whole-mount immunofluorescence labeling with previously characterized antibodies (17)(18)(19)(20) and a Upd enhancer trap line (upd-GAL4) (21). Although α-Stat antibodies have been well described (18), we confirmed the specificity of α-Upd and α-Dome antibodies by using the Gal4-Switch/RNAi system, which allows both spatial and temporal control of gene expression (22) (Fig.…”

The Hippo Pathway Controls Border Cell Migration Through Distinct Mechanisms in Outer Border Cells and Polar Cells of the Drosophila Ovary

“…During border cell induction and migration, JAK/STAT signaling in outer border cells is activated by Upd secreted from polar cells (Silver and Montell 2001;Beccari et al 2002;Ghiglione et al 2002). Since the Hippo pathway is required in polar cells for border cell induction and migration, it is possible that the Hippo pathway controls upd expression cell-autonomously in polar cells.…”

Two distinct but convergent groups of cells trigger Torso receptor tyrosine kinase activation by independently expressing torso-like

“…It is known that the JAK/STAT pathway is required for establishment of the BC fate (14,16,17). Indeed, BC expression of slbo, a gene coding for a transcription factor, is induced by the JAK/STAT pathway (14,16).…”