a–r, Embryos from rifampicin-treated colonies stained for Ubx mRNA in blue (a–c), Tud protein in white (d–f), Aub protein in green (g–i), osk mRNA in blue (j–l), nos mRNA in blue (m–o) or stau mRNA in blue (p–r). a, d, g, j, m, p, Freshly laid stage-1 eggs showing no effect on the number of zones relative to wild type, except for in d Tud in white showing loss of zone 1 relative to wild type. b, e, h, k, n, q, Stage-6 mild-phenotype embryos with no observable morphological defects: asterisks indicate loss of specific mRNAs and proteins of Ubx and germline gene expression. c, f, i, l, o, r, Stage-6 severe-phenotype embryos showing morphological defects and loss or misexpression of germline and Hox genes. d–i, Fluorescent images with DAPI in blue. Zones of germline and Hox gene expression are indicated with arrowheads. Question marks indicate presumptive zones. Anterior is to the left, dorsal is to the top. In situ hybridization and immunohistochemistry experiments were repeated at least 4 times independently on n ≥ 15 embryos per developmental stage.