title: Ecdysteroid-regulated heat-shock gene expression during Drosophila melanogaster development.
abstract: Peaks in hsp 26, 28, and 83 RNA levels are correlated with peaks in ecdysteroid titers during mid-embryogenesis, pupariation, and mid-pupation, and with a peak in the level of RNA from the 74EF ecdysone puff at pupariation. Inhibition of the ecdysteroid peak at pupariation by temperature shift of the conditionally ecdysteroid-deficient strain ecd-1 was followed by a disappearance of hsp 26 RNA and a decline in hsp 83 RNA level; subsequent addition of exogeneous 20-OH-ecdysone to the temperature-shifted strain resulted in a severalfold increase in hsp 83 RNA level, and a dramatic increase in that of hsp 26. These results are consistent with the induction of the hsp 83, 28, and 26 genes by ecdysteroid at several developmental stages.
mesh_terms: D000818:Animals; D004331:Drosophila melanogaster / Q000187:drug effects / Q000235:genetics / Q000254:growth & development*; D004441:Ecdysterone / Q000494:pharmacology; D005796:Genes / Q000187:drug effects; D006360:Heat-Shock Proteins / Q000235:genetics* / Q000302:isolation & purification; D007605:Juvenile Hormones / Q000502:physiology*; D009154:Mutation
chemical_list: D006360:Heat-Shock Proteins; D007605:Juvenile Hormones; D004441:Ecdysterone