ISSN:
1615-6102
Keywords:
Cytokinesis
;
Harveyella
;
Red alga
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Summary A unique type of cytokinesis is described in tetrasporocytes of the alloparasitic red alga,Harveyella sp. Cytokinesis takes place immediately after four post-meiotic nuclei are formed and may result from coalescence of endoplasmic reticulum cisternae. As a result of this cisternal fusion, a double-membraned cleavage channel is formed. This channel lacks wall material and is usually oriented tetrahedrally. Membranes of the peripheral portions of the cleavage channel fuse with the existing tetrasporocyte plasmalemma, delimiting four tetraspores. Subsequently, wall material is secreted within the preformed cleavage channels to form a continuous tetraspore wall between adjacent tetraspores. Wall secretion usually occurs in a centrifugal direction, beginning at the juncture of the cleavage channels, but it also may be random or centripetal. Dictyosome activity is absent during the first wall secretion stage but contributes to secondary wall deposition.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02224419
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