Figure 5. LIN-31 Expression Patterns. Green, anti-LIN-31 staining; red, MH27 staining; blue, DAPI staining.(A) Expression pattern of LIN-31 in wild-type animals at the L2 stage. LIN-31 is expressed in the Pn.p cells (P1.p-P11.p), including the vulval precursor cells (P3.p-P8.p). MH27 stains the cell junctions of P3.p-P8.p at this stage.(B) LIN-31 expression is not observed in
lin-31(
ga37) or in
lin-31(
n1053) animals (P. B. T., unpublished observations).(C) DAPI staining at the L4 stage shows the gonad (large arrows). (D) LIN-31 is expressed in the vulval precursor cell descendants (arrows) but not in the gonad or sex myoblasts, which flank the P6.p progeny during this time.(E) At the L1 larval stage, LIN-31 is not expressed in the excretory duct cell (exc) or in P12.p but is expressed in P1.p to P11.p.(F) At this same stage,
let-23(
mn23) mutants arrest in development indicating prior function of this signaling pathway in cells comprising the excretory system.(G) In males 25 hr after hatching, LIN-31 is expressed in 3 of the 4 B cell progeny (B.a[l or r]pp, B.alap, B.arap, but not B.a[l or r]aa) that utilize LET-23 RTK signaling. Green indicates nuclei expressing LIN-31 located in the sagital ventral midline (same plane as MH27 staining), while blue indicates nuclei expressing LIN-31 located laterally left of the midline. Other cells expressing LIN-31 during the L2/L3 stage in the hermaphrodite include the excretory duct cell (exc) and the neuronal cell T.ppa (known as PVWL/R). Scale bar for (A-G) is 10 μm.