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Expression of the gene BK27 in a Drosophila embryo with an extended germ band. This gene, 
which encodes a homeodomain and a Paired domain, exhibits prominent expression in the 
ventral labial lobe, marking the progenitor cells for the salivary gland placode. The staining seen 
in the head is localized in the subantennal region. 
Research and photograph by Susie Jun in the laboratory of Claude Desplan. 
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