"Expression of reporters normally seen in CA/CPs 1-4 is absent, of course, when P3-P6.aap die in
lin-39 mutants because CA/CPs 1-4 are never generated. In order to see whether
lin-39 function is necessary for expression of reporters in CA/CPs 1-4, we blocked programmed cell death with a
ced-3 mutation: in
lin-39(
n1760);
ced-3(
n1286) double mutants, all P3-P8.aap cells survive. In these mutants, all CP neurons (CP1-CP6) lack serotonin immunoreactivity (data not shown) and fail to express
tph-1::mCherry." (Table 1, Figure 4H)