An apx-1 reporter is expressed in the DTC after the L2 stage,
and APX-1 functions redundantly with LAG-2 to promote germline
proliferation. (A-C) apx-1 expression was examined using
an apx-1 promoter::lacZ fusion
(Chen and Greenwald, 2004) in
the early L1 stage (A, 1 hour), in the early L3 stage (B, 21 hours) and in the
L4 stage (C, 31 hours). All times are post-hatch at 25°C; white arrow
indicates the DTC. White bar underscores the gonad in A. (D)
Time-course analysis of apx-1::lacZ expression in the DTC. The
somatic primordium of the gonad (SPG) forms at the beginning of the L3 stage.
(E) Penetrance of Glp-1-like phenotype (all germ cells in a gonad arm
displaying nuclear morphology consistent with meiotic prophase or
gametogenesis). Synchronous L1 larvae were transferred to RNAi plates, and
fixed and stained with DAPI ∼50 hours later at 20°C. Control RNAi is
L4440 vector. In addition to scoring the Glp-1-like sterile phenotype, less
severe phenotypes were also observed (for a classification of all phenotypes
and a complete description of the RNAi conditions, see Table S2 in the
supplementary material).