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ULTRASTRUCTURAL MORPHOLOGY OF MICROTHAMNION ZOOSPORES 1
Author(s) -
Watson Melvin William,
Arnott Howard J.
Publication year - 1973
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.0022-3646.1973.00015.x
Subject(s) - pyrenoid , biology , ultrastructure , organelle , zoospore , chloroplast , flagellum , contractile vacuole , biophysics , bacterial outer membrane , thylakoid , vacuole , cytoplasm , microbiology and biotechnology , botany , spore , biochemistry , escherichia coli , gene
SUMMARY The Ultrastructure of Microthamnion zoospores is described (exclusive of the finer details of the flagellar apparatus). The zoospores have a typical chlorophycean morphology but, in addition, many unique features. The chloroplasts contain starch but no pyrenoid. Thylakoids may run from one edge of the chloroplast to the other and usually anastomose into 2‐ to 8‐membered stacks. The internal morphology is highly polarized and characterized by an intimate proximity and constant spacing between many organelle membranes. All the organelles are asymmetrically distributed within the cell in a precise manner. The anterior region of the zoospore is attenuated into a neck which contains a single, massive mitochondrion. A fibrous rhizoplast lies beside the mitochondrion and appears to connect the flagellar apparatus directly with the outer membrane of the nuclear envelope. In addition, this outer membrane is extended over a distance of several microns to eventually lie in close proximity to the basal bodies. Oil vacuoles and lipid bodies are restricted to the posterior end of the zoospore.