Surface properties of the euglenoid flagellum.
New structural details of the Euglena flagellum have led to a modified interpretation of the arrangement of the mastigoneme sheath and its internal attachment. A paraaxial ribbon is described which is located between the flagellar membrane and the axonemal microtubules. This fine ribbon apparently binds mastigoneme units and in turn is bonded to three peripheral microtubule doublets in a position approximately opposite that of the paraflagellar rod. The latter structure seems to anchor one half of the flagellar sheath while the paraaxial ribbon anchors the other one half of the flagellar sheath. Immunological labelling of Euglena mastigonemes has demonstrated that mastigonemes are present in the reservoir as well as on the flagellar surface if monovalent Fab' is used on deflagellated cells. Pulse labelling with anti-mastigoneme Fab' in regenerating cells showed the initial reservoir label was lost and indicated that the labelled mastigonemes were transferred to the flagellum. The reservoir is thus demonstrated to contain a surface pool for flagellar mastigonemes. Flagellar regeneration is partially inhibited irreversibly by the glycoprotein synthesis inhibitor tunicamycin. Experiments with cycloheximide and tunicamycin suggest each antibiotic affects different moieties and that some glycoprotein(s) is limiting to flagellar growth in Euglena. It is postulated that mastigonemes are possible candidates for that rate-limiting component.
D000818:Animals; D002462:Cell Membrane / Q000187:drug effects / Q000648:ultrastructure; D003513:Cycloheximide / Q000494:pharmacology; D005055:Euglena / Q000187:drug effects / Q000648:ultrastructure*; D005056:Euglena gracilis / Q000648:ultrastructure; D005407:Flagella / Q000187:drug effects / Q000648:ultrastructure*; D013499:Surface Properties; D014415:Tunicamycin / Q000494:pharmacology
D014415:Tunicamycin; D003513:Cycloheximide