|Relation between chloroplast replication and cell division in Olisthodiscus luteus|In: Plant Science Letters. Elsevier: Shannon. ISSN 0304-4211, more
The number of chloroplasts found in cells of the unicellular alga Olisthodiscus luteus Carter (Chrysophycophyta, Chrysophyceae) at various points of the growth curve were shown to be significantly different. Chloroplast replication and cell division were tightly coupled during the logarithmic phase of growth, while chloroplast replication fell behind cell division when the culture entered the linear growth phase. The chlorophyll content per cell remained constant during the increase of the culture density — thus the amount of chlorophyll per plastid rose with the decline of the chloroplast number per cell. A rapid increase of the cell's chloroplast number prior to the onset of cell division was found in cultures provided with fresh medium. The lower chloroplast number observed in ageing cultures is thought to be due to a limited separation of the chloroplast ER, while the rapid increase of the organelle number in young inocula is interpreted as completion of the last step in chloroplast replication, namely the fission of the chloroplast ER.