Figure 3.

P Bodies in Nurse Cells Contain Similar Proteins as those in the Oocyte but Have Significantly Lower Levels of Orb

(A–D′) Protein detection by IEM on ultrathin frozen sections of nurse cells. Dashed black lines mark the edge of P bodies.

(A–A′′) Anti-Me31B (10 nm) is highly enriched in the core of P bodies in the oocyte (A) and nurse cells (A′). A′′ is a lower-magnification image showing P bodies containing Me31B in both nurse cells and the oocyte. The solid black line marks the boundary between the nurse cells and the oocyte.

(B) Anti-Bru (15 nm) is highly enriched in the P body core and in P bodies at the dorso-anterior corner of the oocyte. Proteins found at the core of P bodies in the oocyte are also detected in nurse cell P bodies by immunofluorescence (Figure S5). The cyan line marks the boundary between the nurse cells and the oocyte.

(C) Anti-ribo 490 (10 nm) shows ribosomes predominantly excluded from P bodies in nurse cells.

(D and D′) Anti-Orb (15 nm) is present in P bodies in the oocyte and is enriched at the edge (D, see also Figure S4), but P bodies in nurse cells contain significantly lower levels of Orb (D′).

(E–E′′) Nurse cell-oocyte boundary of the DA corner of an egg chamber expressing Me31B::GFP (E) stained with anti-Orb (E′) (n = 30). P bodies in the nurse cell cytoplasm express significantly lower levels of Orb compared with in the oocyte. (E) Me31B::GFP labeling P bodies, (E′) Anti-Orb labeling Orb protein, and (E′′′) overlay of Me31B::GFP labeling P bodies in green and anti-Orb labeling Orb protein in red.

Scale bars, 200 nm (A–A′′, B, C, D, and D′) and 10 μm (E).