Fig. 1. Field-emission scanning electron microscopy (feSEM) of spreads of non-injected control Xenopus nuclear envelopes. (A) Nucleoplasmic face of a nuclear envelope. (B) An area of parallel filaments, indicated by top small horizontal arrows in A is shown at higher magnification. (C) Area of highly ordered lamin lattice at high magnification. (D) Nuclear envelopes treated with 0.5% Triton X-100 before fixation to remove membranes. Some filaments that run in parallel are marked by small arrows. Arrowheads in A and D mark lamin-free membrane areas. (E-G) Further examples, from (E) the same and (F,G) different oocytes, showing arrays of parallel filaments. The arrow in E indicates where one set of parallel filaments bifurcates.