Figure 8

Ultrastructure of embryonic and embryophore cells during early and advanced phase of matrotrophic nutrition in Bicellariella ciliata (TEM). The cuticle of the ooecial vesicle is shown with arrowheads, the fertilization envelope (when present) is shown by arrows. A, hypertrophied embryophore epithelial cells with folding zones and surface of the early embryo with infoldings (single membrane limited body filled with flocculent material); B, flocculent material inbetween the cuticle of the embryophore and the fertilization envelope; C, embryonic surface with infoldings adjoined to the ooecium wall; D, part of the embryonic cells showing active endocytosis; E, flocculent material (asterisks) in the brooding cavity inbetween the cuticle of the embryophore and embryonic surface with numerous infoldings; F, surface of late embryo adjoined to the embryophore (seen in the upper right corner) and showing active endocytosis inbetween microvilli (fertilization envelope collapsed, cell border shown with arrows); G, side of late embryo opposite to the embryophore and adjoining the ooecial wall (infoldings between microvilli bases are clearly seen). Abbreviations; bc, brooding cavity; ci, cilia; e, embryo; ed, endocytotic vesicles; eph, epithelial cells of embryophore; fd, foldings of embryophore cells; fm, flocculent material; ga, Golgi apparatus; if, infoldings of the embryonic cells; mi, mitochondria; ns, nucleolus; nu, nucleus; oe, ooecium; oc, ooecial coelom; pp, protein platelet; rer, rough endoplasmatic reticulum; sv, secretory vesicle; v, proximal wall of ooecial vesicle. Scale bars: A, 2.0 μm, B-G, 1.0 μm.