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SEXUAL REPRODUCTION AND MEIOSIS IN PERIDINIUM INCONSPICUUM LEMMERMANN (DINOPHYCEAE)
Author(s) -
Pfiester Lois A.,
Timpano P.,
Skvarla J. J.,
Holt J. R.
Publication year - 1984
Publication title -
american journal of botany
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.218
H-Index - 151
eISSN - 1537-2197
pISSN - 0002-9122
DOI - 10.1002/j.1537-2197.1984.tb11965.x
Subject(s) - biology , zygote , meiosis , homothallism , sexual reproduction , gametogenesis , cell division , ploidy , botany , microbiology and biotechnology , genetics , cell , embryo , mating type , embryogenesis , gene
In Peridinium inconspicuum Lemmermann, sexual reproduction occurs in both nitrogen‐enriched and nitrogen‐deficient media. In this homothallic strain, protoplasmic fusion begins between two thecate gametes; but zygote formation is completed in a space outside the fusing pair. This diploid cell can form a plated theca which is shed as the cell enlarges. This spherical zygote then forms a new non‐plated theca. The process of ecdysis and the formation of a new non‐plated theca is repeated several times. During this process the zygote gradually elongates and by cytoplasmic infurrowing becomes peanut‐shaped. Eventually two cells are formed. The first and second meiotic divisions are greatly separated in time. The first meiotic division occurs in the spherical non‐thecate zygote. The second meiotic division can occur in the peanut‐shaped zygote before it completes cytokinesis. This meiotic division may not be synchronous, occasionally resulting in a trinucleate stage. Eventually four flagellated, haploid products are produced.