develops from expresses pon external sensory organ precursor cell external sensory organ precursor cell pNb antennal olfactory receptor neuron precursor Nbb 2019-12-12T12:01:52Z Terminal daughter cell of an external sensory organ precursor cell pNb in the developing antenna. It may undergo apoptosis or differentiate into an olfactory receptor neuron, depending upon which sensillum it is in. It can be distinguished from the Nba precursor based on its expression of partner of numb (pon). fly_anatomy.ontology FBbt:00048526