Mj. Chretiennotdinet et al., THE CHITINOUS NATURE OF FILAMENTS EJECTED BY PHAEOCYSTIS (PRYMNESIOPHYCEAE), Journal of phycology, 33(4), 1997, pp. 666-672
Filaments ejected by Phaeocystis globosa Scherffel, organized in star-
like structures, were observed and analyzed before and after their dis
charge from cells. Ultrastructural observations obtained after cryofix
ation and cryosubstitution led to a model for their storage within the
cell and for their ejection from the cell. Electron diffraction analy
sis on the ejected filaments demonstrated their chitinous composition.
This technique indicated without ambiguity that each filament was in
fact a whisker-like cr-chitin crystal, with the axes of the correspond
ing polymer chains aligned with the filament's axis. X-ray microanalys
is of the mats of filaments indicated that the silica content suggeste
d by earlier workers was an artifact resulting from the filtration pro
cedure.