Figure 7

Embryophore ultrastructure during active phase of matrotrophic nutrition where embryos possess well-developed cilia in Bicellariella ciliata (TEM). The cuticle of the ooecial vesicle is shown with arrowheads. A, details of the embryophore epithelial cells adjacent to the embryo; B, zone of foldings separated from cilia of embryo by a cuticle (adhesive contact between epithelial cell is shown by arrow); C, part of embryophore showing associated funicular cells; D, part of funicular strand associated with epithelial cell of embryophore; E, embryophore showing depleting activity towards the final phase of larval maturation (bacteria in the brooding cavity shown with arrows). The RER is diminished and the funicular cells cover considerable parts of the epithelial cells. Abbreviations: bc, brooding cavity; ci, cilia; co, coelom of ooecial vesicle; e, embryo; eph, epithelial cells of embryophore; fc, funicular cells; fd, foldings of embryophore cells; ga, Golgi apparatus; mi, mitochondria; mvb, multivesicular body; nu, nucleus; rer, rough endoplasmatic reticulum; sv, secretory vesicle; v, proximal wall of ooecial vesicle. Scale bars: A, C, D, 2.0 μm, B, E, 1.0 μm.