S. Terui et al., SYNCHRONIZATION OF CHLOROPLAST DIVISION IN THE ULTRAMICROALGA CYANIDIOSCHYZON MEROLAE (RHODOPHYTA) BY TREATMENT WITH LIGHT AND APHIDICOLIN, Journal of phycology, 31(6), 1995, pp. 958-961
A system of highly synchronized chloroplast divisions was developed in
the unicellullar red alga Cyanidioschyzon merolae De Luca, Taddei, &
Varano. Chloroplast divisions were examined by epifluorescence microsc
opy following treatments with light and inhibitors. When the cells dur
ing stationary phase were transferred into a new medium under a 12:12
h LD cycle, chloroplasts, mitochondria, and cell nuclei divided synchr
onously in that order soon after the initiation of dark periods. More
than 40% of the cells contained dividing chloroplasts. To obtain a sys
tem of highly synchronized cell division and chloroplast division, the
cells synchronized by a 12:12 h LD cycle were treated with various in
hibitors. Nocodazole and propyzamide did not affect cell and organelle
divisions, whereas aphidicolin markedly inhibited cell-nuclear divisi
ons and cytokinesis and induced a delay in chloroplast division. More
than 80% of the cells contained dividing chloroplasts when cells synch
ronized by light were treated with aphidicolin for 12 h. This synchron
ized system will be useful for studies of the molecular and cellular m
echanisms of organelle divisions.