Fig. 5. Development of the egg cell, zygote and embryo. Ventral parts of open archegonia in the wild type (A-G) and the PpLFY double disruptants (H-K) were observed by light microscopy of a semi-thin section (A) or by CLSM (B-K). Nuclei (A,B,D-H,J,K, arrows) and sperm (C,I, arrowheads). White and brown boxes below images represent uncolored (A,B,H) and brown-colored (C-G,I-K) neck canals. (A-C,H,I) An egg cell before (A,B,H) or after (C,I) sperm invasion. (D,J) An unexpanded zygote. (E) An expanded zygote at the first cell division. (F) A two-cell embryo. (G,K) An unfertilized egg cell. Scale bars: 10 µm in A, 25 µm in B-K.