Mirror represses pipe expression in follicle cells to initiate dorsoventral axis formation in Drosophila.
Dorsoventral (DV) axis formation in Drosophila begins with selective activation of EGFR, a receptor tyrosine kinase (RTK), in dorsal-anterior (DA) ovarian follicle cells. A critical event regulated by EGFR signaling is the repression of the sulfotransferase-encoding gene pipe in dorsal follicle cells, but how this occurs remains unclear. Here we show that Mirror (Mirr), a homeodomain transcription factor induced by EGFR signaling in DA follicle cells, directly represses pipe expression by binding to a conserved element in the pipe regulatory region. In addition, we find that the HMG-box protein Capicua (Cic) supports pipe expression in ventral follicle cells by repressing Mirr in this region. Interestingly, this role of Cic resembles its function in regulating anteroposterior (AP) body patterning, where Cic supports gap gene expression in central regions of the embryo by repressing Tailless, a repressor induced by RTK signaling at the embryonic poles. Thus, related RTK-Cic repressor circuits regulate the early stages of Drosophila DV and AP body axis formation.
Institut de Biologia Molecular de Barcelona-CSIC, Parc Científic de Barcelona, Barcelona 08028, Spain.
María José
MJ
Andreu
Esther
E
González-Pérez
Leiore
L
Ajuria
Núria
N
Samper
Sergio
S
González-Crespo
Sonsoles
S
Campuzano
Gerardo
G
Jiménez
D000818:Animals; D019521:Body Patterning / Q000235:genetics*; D017124:Conserved Sequence; D029721:Drosophila Proteins / Q000096:biosynthesis / Q000235:genetics* / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000166:cytology / Q000196:embryology* / Q000235:genetics / Q000378:metabolism; D004625:Embryo, Nonmammalian / Q000378:metabolism; D066246:ErbB Receptors / Q000378:metabolism*; D005136:Eye Proteins / Q000378:metabolism*; D005260:Female; D018507:Gene Expression Regulation, Developmental; D024002:HMGB Proteins / Q000378:metabolism*; D018398:Homeodomain Proteins / Q000378:metabolism*; D006080:Ovarian Follicle / Q000166:cytology / Q000196:embryology / Q000378:metabolism; D018010:Receptors, Invertebrate Peptide / Q000378:metabolism*; D012045:Regulatory Sequences, Nucleic Acid; D012097:Repressor Proteins / Q000378:metabolism*; D015398:Signal Transduction; D015238:Sulfotransferases / Q000096:biosynthesis / Q000235:genetics* / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism*
D029721:Drosophila Proteins; D005136:Eye Proteins; D024002:HMGB Proteins; D018398:Homeodomain Proteins; D018010:Receptors, Invertebrate Peptide; D012097:Repressor Proteins; D014157:Transcription Factors; C404284:cic protein, Drosophila; C105790:mirr protein, Drosophila; C066532:Egfr protein, Drosophila; D066246:ErbB Receptors; D015238:Sulfotransferases; C115847:pip protein, Drosophila