| Abstract: | Spermatial development and differentiation of wall components were investigated by electron microscopy and cytochemical methods in Antithamnion nipponicum Yamada et Inagaki. The spermatium is composed of two parts, a globular head and two appendages projecting from near the basal portion. The appendages originate form spermatangial vesicles (SVs) and follow a developmental sequence beginning as amorphous material and ending as fully formed fibrous structures compressed with in the SVs. SV formation is due to contributions initially from endoplasmic reticulum and later form dictyosome-derived vesicles. Chemical differentiation of the spermatial wall occurs early in its development. Calcofluor white ST does not label spermatial walls, indicating an absence of cellulose polysaccharides, which are abundant in vegetative cell walls. Labeled lectins show that α-d -methyl manose and / or α-d -glucose as well as N-acetyl-glucosamine, β-d -galactose, and α-l -fucose moieties are present on the spermatial wall but not in the vegetative cell wall. The glyconjugate with α-d -methyl mannose and / or glucose residues, previously reported as a gamete recognition molecule in this species, is distributed along the surface of spermatia as well as in the SV during spermatangial development. |
