ISSN:
1615-6102
Schlagwort(e):
Cell cycle
;
Chloroplast DNA
;
Chloroplast nucleoids
;
DAPI
;
Dunaliella salina
;
Light spectral qualities
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Biologie
Notizen:
Summary Synchronous cultures of the algaDunaliella salina were grown in blue or red light. The relationships between replication of chloroplast DNA, cell size, cell age and the number of chloroplast nucleoids were studied. The replication of chloroplast DNA and the division of chloroplast nucleoids occurred in two separate periods of the chloroplast cycle. DNA replication was concomitant with that in the nucleocytoplasmic compartment but nucleoid division occurred several hours earlier than nuclear division. Red-light-grown cells were bigger and grew more rapidly than those grown in blue light. In newly formed daughter cells, the chloroplast nucleoids were small and spherical and they were localized around the pyrenoid. During the cell cycle they spread to other parts of the chloroplast. The number of DNA molecules per nucleoid doubled during DNA replication in the first third of the cell cycle but decreased several hours later when the nucleoids divided. Their number was fairly constant independent of the different light quality. Cells grown in red light replicated their chl-DNA and divided their nucleoids before those grown in blue light and their daughter cells possessed about 25 nucleoids as opposed to 15.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1007/BF01403672
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