Patterning function of homothorax/extradenticle in the thorax of Drosophila.
In Drosophila, the morphological diversity is generated by the activation of different sets of active developmental regulatory genes in the different body subdomains. Here, we have investigated the role of the homothorax/extradenticle (hth/exd) gene pair in the elaboration of the pattern of the anterior mesothorax (notum). These two genes are active in the same regions and behave as a single functional unit. We find that their original uniform expression in the notum is downregulated during development and becomes restricted to two distinct, alpha and betasubdomains. This modulation appears to be important for the formation of distinct patterns in the two subdomains. The regulation of hth/exd expression is achieved by the combined repressing functions of the Pax gene eyegone (eyg) and of the Dpp pathway. hth/exd is repressed in the body regions where eyg is active and that also contain high levels of Dpp activity. We also present evidence for a molecular interaction between the Hth and the Eyg proteins that may be important for the patterning of the alpha subdomain.
Aldaz
Silvia
S
Centro de Biología Molecular, CSIC-UAM, Universidad Autónoma de Madrid, Madrid, 28049, Spain.
Morata
Ginés
G
Azpiazu
Natalia
N
D000818:Animals; D019521:Body Patterning / Q000502:physiology*; D004268:DNA-Binding Proteins / Q000378:metabolism; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000166:cytology / Q000196:embryology* / Q000235:genetics / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism*; D008957:Models, Genetic; D015398:Signal Transduction; D013909:Thorax / Q000166:cytology / Q000196:embryology* / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D018398:Homeodomain Proteins; D014157:Transcription Factors; C064196:dpp protein, Drosophila; C083405:exd protein, Drosophila; C477040:eyg protein, Drosophila; C108704:hth protein, Drosophila