Distribution of concanavalin a binding carbohydrates during mating in Chlamydomonas.
Cell surface carbohydrates, detected by fluorescein isothiocyanate/concanavalin A (FITC-ConA), were identified at four locations on gametes of Chlamydomonas reinhardtii. (1) The cell wall: uniform labelling with FITC-ConA was observed; a substantial number of sites were localized in the sodium dodecyl sulphate-insoluble inner wall, which contains the flagellar collars. (2) The periplasm: a crescent-shaped area was visualized with FITC-ConA and localized by ferritin-ConA. We were able to recover autolytic activity on a ConA affinity column from the mating medium of wild-type cells after the release of these periplasmic sites. The cell-wall-less mutant CW15 displays no periplasmic sites and demonstrates a corresponding inability to release autolytic activity after mating for 60 min. A model for wall lysis is presented, which considers the involvement of these sites in the lytic process. (3) The mating structure: during mating a small fluorescent plaque-like site was observed on cells at a location corresponding to the carbohydrate-like zone of the mating type minus mating structure and may indicate the involvement of ConA binding material in gametic cell fusion. (4) Secreted products: following cell fusion zygotes begin to secrete ConA positive material at about 1 1/2 h. After 24 h a ConA positive zygote wall and pellicle appear.
D001665:Binding Sites; D050260:Carbohydrate Metabolism; D002473:Cell Wall / Q000378:metabolism; D002696:Chlamydomonas / Q000378:metabolism* / Q000502:physiology / Q000648:ultrastructure; D002846:Chromatography, Affinity; D003208:Concanavalin A / Q000378:metabolism*; D009238:N-Acetylmuramoyl-L-alanine Amidase / Q000302:isolation & purification; D011523:Protoplasts / Q000378:metabolism
D003208:Concanavalin A; D009238:N-Acetylmuramoyl-L-alanine Amidase