In L1 larvae,
swsn-4 expression was previously reported to be ubiquitous (Sawa et al., 2000). At this stage (Pn.p), its expression was confirmed in all Pn.p cells and ventral cord neurons in two independent transgenic lines. At later stages,
swsn-4 continued to be expressed in dividing vulval cells,
hyp7 nuclei, and ventral cord neurons in both lines. However, expression declined substantially in L4 larvae, after completion of vulval induction.