somatic precursor cell primary pigment cell precursor 2009-10-02T10:49:52Z FBbt:00007370 DISAMBIGUATION: The term interommatidial precursor cell is sometimes used to refer to precursors of primary pigment cells as well as secondary and tertiary pigment cells (e.g. Larson et al., 2008), even though primary pigment cells are not interommatidial cells. This is not the case here. Precursor of the primary pigment cells of the retina. From 10 hours after puparium formation, these cells are part of an unstructured pool of undifferentiated cells surrounding each developing ommatidial core. Around 20-23 hours APF, the primary pigment cell precursors leave this pool and become part of the ommatidia. fly_anatomy.ontology