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Mitosis in the dinoflagellate Amphidinium carterae
305 BioSystems, 7 (1975) 305 © North-Holland Publishing Company, Amsterdam -- Printed in The Netherlands
MITOSIS IN THE D I N O F L A G E L L A T E A 3 4 P H I D I N I U M C A R T E R A E BERL R. OAKLEY Department of Botany, University of British Columbia, Vancouver, CA, Canada
Abstract
Details o f mitosis are presented for the free-living marine dinoflagellate A m p h i d i n i u m carterae. In prophase, bundles of microtubules form and sink into invaginations of the nuclear envelope, forming tunnels. These microtubules are associated with microbody-like structures but are not associated with flagellar bases. Each c h r o m o s o m e divides forming a " V , " t he apex
o f which is attached to the mitotic tunnel. At this stage, the c h r o m o s o m e s become attached to microtubules by small " k i n e t o c h o r e s " which extend through the intact nuclear envelope. No metaphase plate is formed. In anaphase, there is an increase in the interpolar distance but the chrom osom e-t o-pol e distance remains relatively constant. Possible mechanisms of chromosomal segregation and movement are proposed and the possible evolutionary significance of these findings was discussed.
MITOSIS IN THE D I N O F L A G E L L A T E A 3 4 P H I D I N I U M C A R T E R A E BERL R. OAKLEY Department of Botany, University of British Columbia, Vancouver, CA, Canada
Abstract
Details o f mitosis are presented for the free-living marine dinoflagellate A m p h i d i n i u m carterae. In prophase, bundles of microtubules form and sink into invaginations of the nuclear envelope, forming tunnels. These microtubules are associated with microbody-like structures but are not associated with flagellar bases. Each c h r o m o s o m e divides forming a " V , " t he apex
o f which is attached to the mitotic tunnel. At this stage, the c h r o m o s o m e s become attached to microtubules by small " k i n e t o c h o r e s " which extend through the intact nuclear envelope. No metaphase plate is formed. In anaphase, there is an increase in the interpolar distance but the chrom osom e-t o-pol e distance remains relatively constant. Possible mechanisms of chromosomal segregation and movement are proposed and the possible evolutionary significance of these findings was discussed.