Figure 6.

Altering P body physical state leads to premature loss of bcd mRNA

(A) Coarse-grained simulations performed with 50 RNA molecules 800 protein molecules in which condensate assembly is driven by both protein-protein and protein-RNA interactions. See also Figure S4G.

(B) Mature oocyte expressing Me31B::GFP, labeled with GFP-Booster and smFISH for bcd mRNA. P bodies and bcd mRNA co-localize at the anterior region. Inset shows a zoomed in version of bcd mRNA and P bodies (n = 10 mature oocytes). Maximum projection 5 μm.

(C–E) Mature oocytes expressing Me31B::GFP, hsp83-MCP-RFP, and bcd-(ms2)₆.

(C) The addition of 1,6-HD causes P bodies and bcd mRNA to initially adopt a spherical shape (t = 10 min), suggestive of a more dynamic physical state (n = 30). Maximum projection, 5 μm.

(D) The addition of PBS does not affect the co-localization of bcd mRNA with P bodies. Although fluorescence of bcd at t = 25 min decreases, this is likely due to photobleaching, the cytoplasmic distribution of bcd mRNA remains similar to t = 0 min (blue) (n = 35). Maximum projection 5 μm.

(E) Extended exposure to 1,6-HD results in the dispersion of bcd mRNAs, whereas P bodies remain condensed (t = 25 min) (n = 55). Maximum projection 5 μm.

(F) Mature oocyte expressing Me31B::GFP, labeled with GFP-Booster and smFISH for bcd mRNA, before and after treatment with 1,6-HD. At t = 0 min, 98% of bcd mRNA particles are co-localized with P bodies. Following treatment with 1,6-HD (t = 25 min), bcd mRNA particles disperse and are not always co-localized with P bodies (52%) (n = 10 mature oocytes). Maximum projection 5 μm.

Scale bar, 10 μm (A), 5 μm (B and F), 1.5 μm (C–E).

See also Figure S5.