May play a role in determining neuronal identity, may be directly involved in specifying identity of individual neurons. Required during embryogenesis for the process of body segmentation. Homeotic protein, required in alternating segment primordia, it specifies the correct number of segments. Expressed early in development in a striped pattern at the blastoderm stage. Later expressed in a specific subset of neuronal precursor cells, neurons and glia in the developing CNS. Between 5 and 6 hours of development, found in the midline precursor-2 cells in a segmentally repeating pattern. Expression in many other neuronal precursors follows and reaches a second peak of abundance at 9 hours of development. Expressed in the hindgut between 11-15 hours of development. Expressed during embryonic development. Phosphorylated at as many as 16 sites. 'Fushi tarazu' means 'segment deficient' in Japanese. Flies lacking ftz exhibit embryos with half the usual number of body segments. Belongs to the Antp homeobox family.