Signaling from germ cells mediated by the rhomboid homolog stet organizes encapsulation by somatic support cells.
Germ cells normally differentiate in the context of encapsulating somatic cells. However, the mechanisms that set up the special relationship between germ cells and somatic support cells and the signals that mediate the crucial communications between the two cell types are poorly understood. We show that interactions between germ cells and somatic support cells in Drosophila depend on wild-type function of the stet gene. In males, stet acts in germ cells to allow their encapsulation by somatic cyst cells and is required for germ cell differentiation. In females, stet function allows inner sheath cells to enclose early germ cells correctly at the tip of the germarium. stet encodes a homolog of rhomboid, a component of the epidermal growth factor receptor signaling pathway involved in ligand activation in the signaling cell. The stet mutant phenotype suggests that stet facilitates signaling from germ cells to the epidermal growth factor receptor on somatic cells, resulting in the encapsulation of germ cells by somatic support cells. The micro-environment provided by the surrounding somatic cells may, in turn, regulate differentiation of the germ cells they enclose.
Schulz
Cordula
C
Departments of Developmental Biology and Genetics, Stanford University School of Medicine, Stanford, CA 94305-5329, USA.
Wood
Cricket G
CG
Jones
D Leanne
DL
Tazuke
Salli I
SI
Fuller
Margaret T
MT
D000818:Animals; D015415:Biomarkers; D002454:Cell Differentiation; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000235:genetics / Q000378:metabolism; D066246:ErbB Receptors / Q000378:metabolism; D005136:Eye Proteins / Q000235:genetics; D005260:Female; D008297:Male; D008565:Membrane Proteins / Q000235:genetics; D010063:Ovum / Q000166:cytology / Q000378:metabolism / Q000502:physiology*; D011494:Protein Kinases; D011518:Proto-Oncogene Proteins / Q000235:genetics; D011956:Receptors, Cell Surface; D018010:Receptors, Invertebrate Peptide / Q000378:metabolism; D015398:Signal Transduction; D013094:Spermatozoa / Q000166:cytology / Q000378:metabolism / Q000502:physiology*; D051155:Wnt1 Protein
D015415:Biomarkers; D029721:Drosophila Proteins; D005136:Eye Proteins; D008565:Membrane Proteins; D011518:Proto-Oncogene Proteins; D011956:Receptors, Cell Surface; D018010:Receptors, Invertebrate Peptide; C081481:Rho protein, Drosophila; C472498:Stet protein, Drosophila; D051155:Wnt1 Protein; C467520:esg protein, Drosophila; C092694:eya protein, Drosophila; C070844:ptc protein, Drosophila; C074622:wg protein, Drosophila; D011494:Protein Kinases; C066532:Egfr protein, Drosophila; D066246:ErbB Receptors