Figure 2. TRA-1 expressed in embryonic and larval SGPs. (A-F) Embryos or larvae stained with anti-TRA-1 antibodies; (A-C,E,F) anti-TRA-1(AS) polyclonal antibody; (D) anti-TRA-1(DZ) peptide antibody. (A,B) Wild-type XX embryo at 320 minutes, when gonadal primordium has just formed; this embryo carries a
hnd-1::GFP reporter to identify SGPs. (A) TRA-1 is present in SGPs (only one is visible) of the newly formed gonadal primordium and appears to be predominantly nuclear. SGP staining is reproducible. PGC staining with anti-TRA-1 is variable and may be non-specific. (B)
hnd-1::GFP identifies SGP shown in A. (C) Wild-type XX threefold embryo with strong nuclear TRA-1 staining. (D) Wild-type XX L1 gonadal primordium. TRA-1 (red) in SGP nuclei (only one is visible); PGCs are identified by anti-NOS-3 (green). (E) Wild-type XX L1 gonadal primordium; TRA-1 in SGPs is predominantly nuclear. (F)
tra-2;
xol-1 XX pseudo-male L1 gonadal primordium. TRA-1 in masculinized SGPs is expressed at a lower level and is distributed between nucleus and cytoplasm; a similar pattern is observed in wild-type XO males (not shown). (G-J) Larvae expressing a TRA-1 translational reporter (GFP::TRA-1). (G,I) DIC images; (H,J) immunofluorescence. (G,H) Wild-type L1 XX hermaphrodite. GFP::TRA-1 is expressed in SGPs (only one is visible) and intestinal cells (int). This rescuing fusion protein is predominantly nuclear. (I,J) Wild-type L1 XO male; GFP::TRA-1 is expressed at a lower level in male SGPs than in hermaphrodite SGPs, and it is distributed through both nucleus and cytoplasm. The exposure in J is longer than that of H to highlight SGP cytoplasmic expression. Expression of GFP::TRA-1 in intestinal cells is not regulated in a sex-specific manner; it therefore serves as a measure of relative exposure between H and J.