Figure 4.
Lack of s38 protein causes disintegration of chorion’s radial complexity. (A,B) Transmission-electron-microscopy images of main-body eggshell from control (c355-GAL4/+) stage-14 follicles, illustrating all typical structures of the tripartite endochorion. (C–H) Transmission electron micrographs of eggshell’s ultrastructural organization in s38-downregulated (c355 > s38_RNAi) follicles revealing phenotypic variation of endochorion’s dysmorphia. (C–F) Unpredictable and stochastic endochorionic assemblies, bearing some architectural elements of a typical endochorion, albeit with thinner fragmented floor and roof structures, less prominent pillars, and larger in size cavities full of loose material (as compared to control ones). (G) Completely disintegrated endochorion structure, containing randomly arranged clumps of endochorionic material. (H) Follicle with entirely collapsed endochorion, but without detectable morphological deformities in the ICL or vitelline membrane. Number of follicles examined: control = 9, s38-downregulated = 17. OC: Oocyte, VM: Vitelline Membrane, ICL: Inner Chorionic Layer, F: Floor, P: Pillar(s), R: Roof, EX: Exochorion, RN: Roof Network and FC: Follicle Cell(s). Scale Bars: 0.5 μm.