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ANALYSIS OF GAMETIC PROTOPLAST RELEASE IN THE CLOSTERIUM PERACEROSUM‐STRIGOSUM‐LITTORALE COMPLEX (CHLOROPHYTA) 1
Author(s) -
Sekimoto Hiroyuki,
Fujii Tadashi
Publication year - 1992
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.0022-3646.1992.00615.x
Subject(s) - protoplast , biology , cell wall , botany
ABSTRACT A biologically active glycoprotein (protoplast‐release‐inducing protein; PR‐IP), which induces the release of gametic protoplasts from mating type minus (mt ‐ ) cells of the Closterium peracerosum‐strigosum‐littorale complex, was prepared from a medium in which mt ‐ and mt + cells had been previously incubated together. The process of PR‐IP‐inducing protoplast release was analyzed. Induction of protoplast release was dependent upon the duration of both PR‐IP treatment and preincubation in nitrogen‐deficient mating medium before PR‐IP treatment. Low cell density in the preculture stage had a significant stimulative effect upon the induction of protoplast release. Light was necessary for protoplast release, especially just before PR‐IP treatment. Chloramphenicol and 3‐(4‐chlorophenyl)‐1,1‐dimethylurea (CMU) exerted inhibitory effects on protoplast release, especially when they were applied to the preculture stage but not when they were applied to the protoplast‐releasing stage after the PR‐IP treatment. We suggest that preculture at a low cell density under continuous light conditions that may cause metabolic changes in the chloroplast is a very important stage for gametic protoplast release in this Closterium .