The hippo pathway promotes Notch signaling in regulation of cell differentiation, proliferation, and oocyte polarity.
Specification of the anterior-posterior axis in Drosophila oocytes requires proper communication between the germ-line cells and the somatically derived follicular epithelial cells. Multiple signaling pathways, including Notch, contribute to oocyte polarity formation by controlling the temporal and spatial pattern of follicle cell differentiation and proliferation. Here we show that the newly identified Hippo tumor-suppressor pathway plays a crucial role in the posterior follicle cells in the regulation of oocyte polarity. Disruption of the Hippo pathway, including major components Hippo, Salvador, and Warts, results in aberrant follicle-cell differentiation and proliferation and dramatic disruption of the oocyte anterior-posterior axis. These phenotypes are related to defective Notch signaling in follicle cells, because misexpression of a constitutively active form of Notch alleviates the oocyte polarity defects. We also find that follicle cells defective in Hippo signaling accumulate the Notch receptor and display defects in endocytosis markers. Our findings suggest that the interaction between Hippo and classic developmental pathways such as Notch is critical to spatial and temporal regulation of differentiation and proliferation and is essential for development of the body axes in Drosophila.
Yu
Jianzhong
J
Department of Biological Science, Florida State University, Tallahassee, Florida, United States of America.
Poulton
John
J
Huang
Yi-Chun
YC
Deng
Wu-Min
WM
D000818:Animals; D002454:Cell Differentiation / Q000502:physiology*; D016764:Cell Polarity / Q000502:physiology*; D049109:Cell Proliferation; D004330:Drosophila; D029721:Drosophila Proteins / Q000502:physiology*; D047908:Intracellular Signaling Peptides and Proteins / Q000502:physiology*; D009865:Oocytes / Q000166:cytology*; D017346:Protein Serine-Threonine Kinases / Q000502:physiology*; D051880:Receptors, Notch / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology*; D000099317:Hippo Kinases
D029721:Drosophila Proteins; D047908:Intracellular Signaling Peptides and Proteins; D017346:Protein Serine-Threonine Kinases; D051880:Receptors, Notch; C499474:hpo protein, Drosophila; D000099317:Hippo Kinases