pax-3 reporter expression was first observed around 240 min post first cleavage in AB-derived cells. Specifically, on the left side of the embryo expression was seen in
hyp4,
hyp6, two hyp 7 cells, P1/2 L, P3/4 L, seam cell V3L, P5/6 L, P7/8 L, P9/10 L, and four cells clustered at the posterior end of the embryo (TL, hyp 7, PVQL, PHBL).
pax-3 reporter expression continued in many of these cells to the end of embryogenesis. In agreement with Liu et al., in the newly hatched L1 larva
pax-3 reporter expression was seen in eight of twelve P cells (P1/2, P5/6, P7/8, P9/10) (Liu et al., 2009). Interestingly
pax-3 reporter expression in P cell pairs P3/4 begins to fade in the embryo and is absent in the L1 stage, and expression was never observed in P cell pair P11/12.
pax-3 reporter expression continued in the Pn.a and Pn.p descendants of these P cells in the L2 stage, but disappeared in the P cell descendants by the beginning of the L3 stage. Using the rescuing
pax-3p::
pax-3::gfp reporter, evidence of
pax-3 expression was also observed in the VulF cells of the L4 stage developing vulva, in the migrating sex myoblasts (SM) and their descendants, and in the developing male tail. In summary,
pax-3 expression was seen throughout embryogenesis and early larval development predominantly in hypodermal cells, in particular the ventral P hypodermal cells.