ftz-f1 and Hr39 opposing roles on EcR expression during Drosophila mushroom body neuron remodeling.
Developmental axon pruning is a general mechanism that is required for maturation of neural circuits. During Drosophila metamorphosis, the larval-specific dendrites and axons of early γ neurons of the mushroom bodies are pruned and replaced by adult-specific processes. We found that the nuclear receptor ftz-f1 is required for this pruning, activates expression of the steroid hormone receptor EcR-B1, whose activity is essential for γ remodeling, and represses expression of Hr39, an ftz-f1 homologous gene. If inappropriately expressed in the γ neurons, HR39 inhibits normal pruning, probably by competing with endogenous FTZ-F1, which results in decreased EcR-B1 expression. EcR-B1 was previously identified as a target of the TGFβ signaling pathway. We found that the ftz-f1 and Hr39 pathway apparently acts independently of TGFβ signaling, suggesting that EcR-B1 is the target of two parallel molecular pathways that act during γ neuron remodeling.
Institute of Human Genetics, CNRS UPR1142, Montpellier, France.
Ana
A
Boulanger
Christelle
C
Clouet-Redt
Morgane
M
Farge
Adrien
A
Flandre
Thomas
T
Guignard
Céline
C
Fernando
François
F
Juge
Jean-Maurice
JM
Dura
D000818:Animals; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D004330:Drosophila; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D018507:Gene Expression Regulation, Developmental / Q000235:genetics / Q000502:physiology*; D008675:Metamorphosis, Biological / Q000235:genetics / Q000502:physiology*; D024521:Mushroom Bodies / Q000254:growth & development / Q000378:metabolism*; D050505:Mutant Proteins / Q000378:metabolism / Q000502:physiology; D009474:Neurons / Q000378:metabolism* / Q000502:physiology; D011987:Receptors, Steroid / Q000235:genetics / Q000378:metabolism* / Q000502:physiology*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D050505:Mutant Proteins; D011987:Receptors, Steroid; D014157:Transcription Factors; C055469:ecdysone receptor; C080885:nuclear hormone receptor FTZ-F1 beta, Drosophila; C499712:nuclear hormone receptor FTZ-F1, Drosophila