Sequence-specific transcription factor which is part of a developmental regulatory system that provides cells with specific positional identities on the anterior-posterior axis. Isoform M and isoform R are expressed in ectodermal and mesodermal tissues and central nervous system of fourth to ninth embryonic abdominal segments. Later in embryogenesis, expression is seen in visceral mesoderm surrounding hindgut and in two Malpighian tubules. Highly expressed during embryogenesis, lower expression in larvae, pupae and adults. Belongs to the Abd-B homeobox family.