In wild-type animals, during the mid-L4,
ida-1::gfp expression is initiated as the cells begin to differentiate, and then the expression persists into adulthood. Consequently, a subset of cells are positive for GFP in mid-L4, whereas all UV1 cells (two per side) are GFP positive 24 h later in the young adult stage.
sptf-3(
gu85) mutants exhibit a similar subset of GFP-positive
uv1 cells in the mid-L4 stage, but fail to sustain robust expression into the adult stage.