Fig. 3. Abd-B expression pattern in wild type and deficiency mutants. HRP staining with antibodies against Abd-B. After staining, the central nervous systems were dissected out from 12 hour-old embryos. In wild type, the typical Abd-B expression pattern is characterized by an anterior-to-posterior gradient from PS10 to 13 in the number of expressing nuclei per parasegment, as well as by the intensity in each nucleus. See text for the description of the expression patterns in the different mutants.