Signalling pathways involved in adult heart formation revealed by gene expression profiling in Drosophila.
Drosophila provides a powerful system for defining the complex genetic programs that drive organogenesis. Under control of the steroid hormone ecdysone, the adult heart in Drosophila forms during metamorphosis by a remodelling of the larval cardiac organ. Here, we evaluated the extent to which transcriptional signatures revealed by genomic approaches can provide new insights into the molecular pathways that underlie heart organogenesis. Whole-genome expression profiling at eight successive time-points covering adult heart formation revealed a highly dynamic temporal map of gene expression through 13 transcript clusters with distinct expression kinetics. A functional atlas of the transcriptome profile strikingly points to the genomic transcriptional response of the ecdysone cascade, and a sharp regulation of key components belonging to a few evolutionarily conserved signalling pathways. A reverse genetic analysis provided evidence that these specific signalling pathways are involved in discrete steps of adult heart formation. In particular, the Wnt signalling pathway is shown to participate in inflow tract and cardiomyocyte differentiation, while activation of the PDGF-VEGF pathway is required for cardiac valve formation. Thus, a detailed temporal map of gene expression can reveal signalling pathways responsible for specific developmental programs and provides here substantial grasp into heart formation.
Zeitouni
Bruno
B
Institut de Biologie du Développement de Marseille-Luminy, Université de la Méditerranée, Marseille, France.
Sénatore
Sébastien
S
Séverac
Dany
D
Aknin
Cindy
C
Sémériva
Michel
M
Perrin
Laurent
L
D000818:Animals; D029721:Drosophila Proteins / Q000378:metabolism; D004331:Drosophila melanogaster; D004440:Ecdysone / Q000378:metabolism; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D016678:Genome; D006321:Heart / Q000502:physiology*; D007700:Kinetics; D009206:Myocardium / Q000378:metabolism; D020411:Oligonucleotide Array Sequence Analysis; D010982:Platelet-Derived Growth Factor / Q000378:metabolism; D015398:Signal Transduction; D014158:Transcription, Genetic; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism
D029721:Drosophila Proteins; D010982:Platelet-Derived Growth Factor; D042461:Vascular Endothelial Growth Factor A; D004440:Ecdysone