Figure 3. Immunolocalization of the LET-99 protein in one-cell embryos. Confocal sections of mitotic stage wild-type embryos (A-J,M-N) and let-99
) embryos (K,O) and meiotic stage wild-type (Q-V) and let-99
) (W,X) embryos stained with affinity-purified LET-99 antibodies (A-D,I-K,Q,S,U,W) and DAPI (E-H,M-O,R,T,V,X). Anterior is towards the left in this and all subsequent figures unless indicated. (A,E) Early prophase embryo during pronuclear migration. (B,F) One-cell prophase embryo during centration, before nuclear rotation has occurred. (C,G) One-cell metaphase embryo. (D,H) One-cell anaphase embryo. (I,M) Two-cell embryo in which P1 is in prophase. (J,N) Six-cell embryo in which P2 is in prophase. (K,O) One-cell let-99
anaphase embryo. Arrowheads indicate polar bodies that are positive for LET-99 staining in wild-type embryos and negative for LET-99 in mutant embryos. Arrows in C,D indicate the metaphase plate- (C) and the spindle midzone- (D) associated staining of LET-99. Arrow in J indicates the LET-99 band in the P2 cell. (L,P) Schematic diagram of one-cell and two-cell embryos showing the three LET-99 domains in P lineage cells: anterior domain, posterior band and posterior domain. (Q,R) Wild-type embryo in anaphase of meiosis. (S,T) Wild-type embryo in metaphase of meiosis viewed from the side; the spindle axis is parallel to the edge of the embryo and tilted slightly towards viewer. arrows in T indicate faint gaps in DAPI staining between opposed chromatin masses to which the bars of LET-99 appear to localize. Such gaps and corresponding LET-99 bars were visible in meiotic prometaphase as well. (U,V) Wild-type embryo in meiosis viewed from one spindle pole. (W,X) let-99
) embryo in anaphase of meiosis. Scale bars: in O, 10 um for A-O; in X, 10 um for Q-X.