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	Figure I. Identification of Xenopus lamin Ln in oocyte nuclear envelopes. Nuclear envelopes from 50 oocytes (A-D), or follicle ceils derived from 25 oocytes (E) were salt washed and proteins electrophoretically separated by two-dimensional gel electrophoresis (first dimension, NEPHGE; second dimension, SDS-PAGE). Proteins were transferred to nitrocellulose filters and stained with Ponceau S to determine the position of the coelectrophoresed marker proteins actin, BSA, and PGK. The filters were probed with the antilamin Lm antibody 46F7 (A), the antilamin LII antibody X223 (B and E), or the antilamin Ln/Lm antibody X155 (D). The filter shown in A was reprobed with the antilamin LII antibody X223 (C). Arrowheads (A-C and F) mark the position of the quantitatively major isoelectric variant of oocyte lamin Ln. Brackets (D), indicate the isoelectric variants of L~ and Lm recognized by the antibody X155.
	Figure 2. Immunolocalization of lamin La in ovary. Indirect immunofluorescence microscopy on Xenopus ovary sections after incubation with antilamin Lm antibody 46F7 (A) or antilamin Lu antibody X223 (B). Chromatin staining (A~ B') by HOECHST. Bar, 50um.
	Figure 3. EM immunolocalization of lamin L~ to the oocyte nuclear lamina. Isolated oocyte nuclear envelopes were incubated with antilamin LI~ antibody X223 followed by secondary antibodies conjugated to 10-nm colloidal gold. Gold particles are observed exclusively on the nucleoplasmic (N) side of the envelope. Nuclear pore complexes are marked by arrowheads. C, cytoplasmic side. Bar, 0.2 um.
	Figure 4. Immunolocalization of lamins in two-cell-stage embryos by indirect immunofluorescence microscopy. Squashed preparations of in vitro fertilized embryos halted in interphase at the two-cell stage by cycloheximide were incubated with antilamin Lm antibody 46F7 (A) or antilamin LI~ antibody X223 (B), followed by Texas red-conjugated secondary antibodies. Chromatin staining (.4' and B') by HOECHST. Bar, 50um.
	Figure 5. EM analysis of egg extract fractionated by ultracentrifugation. Representative examples of materials found in the S~oo Sup. (A), $2oo Cytosol (B), and $2oo Pellet (C) are shown. Bar, 0.2 um.
	Figure 6. Distribution of nuclear envelope proteins in egg extract fractionated by ultracentrifugation. Proteins from the $1o0 Sup. (lane 1 ), serial dilutions of $2oo Cytosol (lanes 2-5), and $20o Pellet (lanes 6-8) were separated by 11% SDS-PAGE. Proteins were transferred to nitrocellulose filters then probed with anti-gp62 antiserum (A), anti-p54 antiserum (B), antilamin L./L,I antibody X155 (C), and antilamin Lm antibody 46F7 (D). Units refers to the relative amount of St0o Sup. (1.0 U equals 2.4 #1 of Si0o Sup., lane 1) contained in the $20o Cytosol (lanes 2-5) and $20o Pellet (lanes 6-8) aliquots used for gel separation.
	Figure 7. Immunoabsorption of vesicles to magnetic beads coated with antilamin antibodies. EM analysis of vesicles from S~0o Sup. immunoabsorbed to magnetic beads coated with control goat anti-mouse antibody (A), antilamin L~I antibody X223 (B), or antilamin Lm antibody 46F7 (C; D, higher magnification image of 46F7-absorbed vesicles). Bars, 0.2 #m (A-C); 0.1 #m (D).
	Figure 8. Immunological analysis of lamins absorbed to antibody-coated magnetic beads. An aliquot of S~0o Sup.- (lane 1 ) and proteins absorbed to control (lane 2)-, antilamin Lm antibody 46F7 (lane 3)-, and antilamin Ln antibody X223 (lane 4)- coated magnetic beads were solubilized, separated by 8 % SDS-PAGE, then transferred to nitrocellulose filters for probing with the antilamin LII/Lm antibody X155. Arrowheads indicate the migration position of the antibody heavy chains (HC) and lamins Lm and Ln are noted on the right of the panel.
	Figure 9. EM immunolocalization of lamins Ln and Lm on membranes present in the $200 Pellet. Membranes were immobilized onto glass coverslips and incubated with the antibodies X223 (A-E) or 46F7 (F-L). Bound antibodies were visualized with secondary antibodies conjugated to 12-nm colloidal gold. Overviews A (X223) and F (46F7) are shown at identical magnifications. Arrows in the overviews (A and F) designate vesicles labeled with gold particles. Higher magnification images of antibody X223-1abeled vesicles (B-E) and 46FTlabeled vesicles (G-L) are also presented. Bars, 0.2 #m (A and F); 0.1 #m (B-E and G--L).

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