Cytochemical studies on the antheridial mucilage and changes in its concentration and amount during the spermatogenesis in Chara vulgaris L.

The internal space of the antheridium in Chara vulgaris L. is filled with the PAS-positive mucilage which is of pectic nature. Morphometric and cytophotometric measurements on the semithin sections indicate that the concentration and amount of PAS-positive polysaccharides: 1) increase during the time of antheridial growth accompanying the phase of antheridial filament divisions, 2) these parameters have the maximum after spermatid formation and at the beginning of their differentiation, i.e. spermiogenesis, 3) both concentration and amount of this substance decrease at the end of spermiogenesis. A decrease in mucilage concentration is also observed in the young antheridia after 3 days of continuous darkness. The results suggest that PAS-positive mucilagenous material is a nutritive substance, accumulated in the first phase of antheridial development and utilized mainly in spermiogenesis. These substances may also be used up in the young antheridia during the lack of energy supply. The autoradiographic studies with the use of a 3H-glucose and 3H-galactose mixture seem to confirm these suggestions.