Cell cycle and organelle division cycle in Cyanidioschyzon merolae

Abstract

A cell replicates by duplicating cellular contents and then dividing into two daughter cells. This is known as the cell cycle, which is characterized by the dynamics of the cell nucleus. However, eukaryotic cells contain organelles other than the nucleus, such as mitochondria, chloroplasts, peroxisomes, endoplasmic reticulum (ER), Golgi bodies, and vacuoles. To understand reproduction of cells, the division and inheritance of organelles as well as the mitotic cycle should be investigated. However, model animal cells and plant cells contain multiples of these organelles which exhibit complex shapes. Therefore, it has been difficult to elucidate their division and inheritance. In contrast, the red alga Cyanidioschyzon merolae possesses a minimum set of organelles. Because of its simple cellular architecture, the dynamics and mechanisms underlying its cell division and inheritance have been investigated. In addition, cell cycle stages of C. merolae have been determined using an S phase-specific marker proliferating cell nuclear antigen (PCNA) and an M phase-specific marker H3S10ph. In this chapter, I introduce the timing of division and inheritance of organelles during the cell cycle in C. merolae and application of the synchronous culture to transcriptome analysis for identifying novel genes related to the division and inheritance of organelles.