The Hox gene Abd-B controls stem cell niche function in the Drosophila testis.
Proper niche architecture is critical for stem cell function, yet only few upstream regulators are known. Here, we report that the Hox transcription factor Abdominal-B (Abd-B), active in premeiotic spermatocytes of Drosophila testes, is essential for positioning the niche to the testis anterior by regulating integrin in neighboring somatic cyst cells. Abd-B also non-cell-autonomously controls critical features within the niche, including centrosome orientation and division rates of germline stem cells. By using genome-wide binding studies, we find that Abd-B mediates its effects on integrin localization by directly controlling at multiple levels the signaling activity of the Sev ligand Boss via its direct targets src42A and sec63, two genes involved in protein trafficking and recycling. Our data show that Abd-B, through local signaling between adjucent cell types, provides positional cues for integrin localization, which is critical for placement of the distant stem cell niche and stem cell activity.
Centre for Organismal Studies (COS) Heidelberg, Heidelberg University, D-69120 Heidelberg, Germany. Electronic address: fani.papagiannouli@bioquant.uni-heidelberg.de.
Fani
F
Papagiannouli
Centre for Organismal Studies (COS) Heidelberg, Heidelberg University, D-69120 Heidelberg, Germany; Deutsches Krebsforschungszentrum (DKFZ), D-69120 Heidelberg, Germany.
Lisa
L
Schardt
Centre for Organismal Studies (COS) Heidelberg, Heidelberg University, D-69120 Heidelberg, Germany.
Janin
J
Grajcarek
Centre for Organismal Studies (COS) Heidelberg, Heidelberg University, D-69120 Heidelberg, Germany.
Nati
N
Ha
Centre for Organismal Studies (COS) Heidelberg, Heidelberg University, D-69120 Heidelberg, Germany. Electronic address: ilohmann@flydev.org.
Ingrid
I
Lohmann
D053687:Adult Stem Cells / Q000166:cytology / Q000378:metabolism / Q000502:physiology; D000818:Animals; D002455:Cell Division; D018385:Centrosome / Q000378:metabolism; D004330:Drosophila / Q000166:cytology / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D005136:Eye Proteins / Q000235:genetics / Q000378:metabolism; D049750:Genome, Insect; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism*; D016023:Integrins / Q000235:genetics / Q000378:metabolism; D008297:Male; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding; D016392:Proto-Oncogene Proteins pp60(c-src) / Q000235:genetics / Q000378:metabolism; D020794:Receptor Protein-Tyrosine Kinases / Q000235:genetics / Q000378:metabolism; D018000:Receptors, Peptide / Q000235:genetics / Q000378:metabolism; D013090:Spermatocytes / Q000166:cytology / Q000378:metabolism / Q000502:physiology; D055153:Stem Cell Niche; D013737:Testis / Q000166:cytology* / Q000254:growth & development / Q000378:metabolism
C062393:Abd-B proteins, Drosophila; D029721:Drosophila Proteins; D005136:Eye Proteins; D018398:Homeodomain Proteins; D016023:Integrins; D008562:Membrane Glycoproteins; D018000:Receptors, Peptide; C072141:boss protein, Drosophila; D020794:Receptor Protein-Tyrosine Kinases; C056737:sev protein, Drosophila; D016392:Proto-Oncogene Proteins pp60(c-src); C100382:Src42A protein, Drosophila