Comparative fine structure of pellicular cytoskeleton in EuglenaEhrenberg

Abstract

The cells of euglenoid flagellates possess a peculiar structural complex located under the plasmalemma, known as the pellicular complex or pellicle. So far this structure has been investigated in a limited number of species; comparative aspects have been neglected. The present study is based on the following 14 Euglena strains, grown in the Collection of Photosynthetic Microorganisms of the Institute of Biological Research, Cluj-Napoca, or collected from different water bodies located near Cluj-Napoca (Romania): E acusEhr., E texta(Duj.) Hübner, E oxyurisSchmarda, E. viridisEhr., E. stellataMainx, E. geniculataDuj., E. tristellaChu, E. pisciformisKlebs, E. gracilisKlebs, E. splendensDang., E. polymorphaDang., E. sanguineaEhr., E. desesEhr. and E. mutabilisSchmitz. Species with a high degree of metaboly exhibit a narrower strip, a thinner membrane cytoskeleton, and the plate-like projections may be absent. Species with a low degree of metaboly or rigid ones possess broad, thick pellicular strips and long plate-like projections. Microtubules may be absent (e. g. E. texta). The present investigation has shown that the peripheral cytoskeleton of Euglena species is relatively homogeneous and based on the same structural model, which differs in various species in relation to the degree of metaboly.