An Ultrastructural Study of the Flagellar Surface Coat in Selected Chlamydomonas Species

Abstract

This investigation has demonstrated the existence of mastigonemes on gametes of Chlamdyomonas reinhardtii and on both vegetative and gametic cells of C. moewussii and C. eugametos. The length and diameter of C. reinhardtii’s mastigonemes were different from those of the latter two species. Gamone, the gamete adhesive substance, has been isolated by the techniques of previous investigators and found to be not a single molecular species but flagellar-membrane vesicles and mastigonemes. Attempts to identify which component of this “crude” gamone fraction caused agglutination of gametes were inconclusive. Of the eight different cytochemical procedures used, only one, PTA-sucrose negative staining, was able to detect and preserve mastigonemes. In this respect, the presence of mastigonemes was useful as an indicator of the quality of the various cytochemical procedures employed. Ruthenium red and concanavalin A-peroxidase treatments revealed globules along the entire length of the flagella surface. The possibility that the globules might be artifacts is discussed.