Engrailed and polyhomeotic maintain posterior cell identity through cubitus-interruptus regulation.
In Drosophila, the subdivision into compartments requires the expression of engrailed (en) and hedgehog (hh) in the posterior cells and of cubitus-interruptus (ci) in the anterior cells. Whereas posterior cells express hh, only anterior cells are competent to respond to the hh signal, because of the presence of ci expression in these cells. We show here that engrailed and polyhomeotic (ph), a member of the Polycomb Group (PcG) genes, act concomitantly to maintain the repression of ci in posterior compartments during development. Using chromatin immunoprecipitation (ChIP), we identified a 1 kb genomic fragment located 4 kb upstream of the ci coding region that is responsible for the regulation of ci. This genomic fragment is bound in vivo by both Polyhomeotic and Engrailed. In particular, we show that Engrailed is responsible for the establishment of ci repression early during embryonic development and is also required, along with Polyhomeotic, to maintain the repression of ci throughout development.
Institut de Génétique Humaine, UPR1142, Montpellier, Herault, France.
Grégory
G
Chanas
Sergey
S
Lavrov
Florence
F
Iral
Giacomo
G
Cavalli
Florence
F
Maschat
D000818:Animals; D030801:Animals, Genetically Modified; D001665:Binding Sites; D019521:Body Patterning / Q000235:genetics; D019070:Cell Lineage; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D004330:Drosophila / Q000196:embryology* / Q000235:genetics; D029721:Drosophila Proteins / Q000235:genetics* / Q000378:metabolism; D004625:Embryo, Nonmammalian; D004627:Embryonic Induction / Q000235:genetics; D018507:Gene Expression Regulation, Developmental; D020868:Gene Silencing; D018398:Homeodomain Proteins / Q000235:genetics* / Q000378:metabolism; D009698:Nucleoproteins / Q000235:genetics* / Q000378:metabolism; D063150:Polycomb Repressive Complex 1; D012045:Regulatory Sequences, Nucleic Acid; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism
D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; C063459:En protein, Drosophila; D018398:Homeodomain Proteins; D009698:Nucleoproteins; D014157:Transcription Factors; C092937:ci protein, Drosophila; C072820:ph-d protein, Drosophila; D063150:Polycomb Repressive Complex 1