Premium
THE INTRAMEMBRANOUS PARTICLE PROFILE OF THE PARAMYLON MEMBRANE DURING PARAMYLON SYNTHESIS IN EUGLENA (EUGLENOPHYCEAE) 1
Author(s) -
Kiss John Z.,
Vasconcelos Aurea C.,
Triemer Richard E.
Publication year - 1988
Publication title -
journal of phycology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.85
H-Index - 127
eISSN - 1529-8817
pISSN - 0022-3646
DOI - 10.1111/j.1529-8817.1988.tb04229.x
Subject(s) - euglena gracilis , membrane , biology , biophysics , biochemistry , chloroplast , gene
Paramylon is the β‐1, 3‐glucan storage product in euglenoid algae. It is a fibrous crystal that occurs as membrane‐bound granules in the cytosol. The role of the surrounding membrane in paramylon synthesis was investigated by the use of freeze‐etch electron microscopy. When Euglena gracilis Klebs strain Z (Pringsheim) cells were frozen in supercooled liquid nitrogen, the fracture plane primarily was throuh the paramylon membrane. A large intramembranous particle (IMP, mean diam range 5.6‐6.5 nm) and a small IMP (mean diam range 9.6‐10.3 nm) were predominant in both PF (protoplasmic fracture) and EF (exoplasmic fracture) faces of the paramylon membrane. During paramylon synthesis induction, the ratio of small to large IMPs increased in both fracture faces. The IMP density decreased in both fracture faces concomitant to paramylon synthesis increase. These changes in IMP profile and density suggest that the paramylon membrane is involved in the synthesis of paramylon.