Pair-rule protein that determines both the size and polarity of even-numbered as well as odd-numbered parasegments during embryogenesis. DNA-binding transcription factor that acts primarily as a transcriptional repressor but can also function as a transcriptional activator, depending on the stage of development and spatial restrictions (By similarity). May function redundantly with odd and drm in leg joint formation during the larval stages, acting downstream of Notch activation. Has two temporally distinct modes of expression during early embryogenesis; expressed in seven stripes at the blastoderm stage. Also expressed in a non-periodic domain at the anterior of the embryo. During gastrulation, the seven primary stripes are supplemented by seven secondary stripes that appear in alternate segments. This results in the labelling of each of the 14 segments in the extended germ band. Expression is relatively weak at the blastoderm stage, gaining in intensity at gastrulation. Expressed in the invaginating stomodeum and proctodeum of the embryonic gut. By stage 13, expressed in the region that will form the proventriculus and in a wide ring at the most posterior portion of the midgut. Expression continues in the gut through the remainder of embryogenesis. Expressed in the proximal Malpighian tubules, brain and pharyngeal muscles during late embryogenesis. Expressed weakly in a segmentally repeated pattern in the leg disk at the distal edge of each presumptive leg segment except in tarsal segments 1 to 4.