Figure 3.

Analysis of endolysosomal organelles in pgp-2(−) embryos. Intestinal cells in wild-type 1.5-fold–stage embryos contained acridine orange–stained, acidified compartments (A) that were significantly reduced in both number and intensity in similarly staged pgp-2(−) embryos (B). Wild-type 1.5-fold–stage embryos contained intestinal organelles stained with anti-FUS-1 (C) and anti-VHA-11 antibodies (E) that were not present in pgp-2(−) embryos (D and F). Compared with wild type (G), the number and morphology of organelles marked with GLO-1::GFP (white arrows) was dramatically reduced and altered in pgp-2(−) embryos (H). Antibodies that recognize VPS-27 stained similar organelles in 1.5-fold–stage wild-type (I) and pgp-2(−) (J) embryos. Anti-GFP antibody staining was used to analyze wild-type and pgp-2(−) pretzel-stage embryos expressing RAB-7 (K and L), LMP-1 (M and N), RME-8 (O and P), RME-1 (Q and R), and RAB-5 (S and T) GFP fusion proteins. The appearance of organelles marked by these proteins was unaltered in pgp-2(−) with the exception of LMP-1::GFP, which was localized to slightly enlarged organelles in pgp-2(−) embryos (white arrow in N). In both wild-type (U and V) and pgp-2(−) (W and X) pretzel-stage embryos, birefringent material is present within acidified intestinal organelles (white arrows). Intestinal cells are located between the black arrowheads.