Synchronous Division in Chlamydomonas moewusii

Abstract

Mass cultures of Chlamydomonas moewusii have been synchronized by means of light-dark shifts. Division of at least 91 percent of the population was made to occur in 1/24 of the life cycle of the cells. The advantages of working with synchronized cultures of obligate autotrophs are discussed.

Characterization of cell-cycle-driven and light-driven gene expression in a synchronous culture system in the unicellular rhodophyte Cyanidioschyzon merolae

“…Another method of synchronization involves application of reversible inhibitors that block the cell cycle at a specific phase (Planchais et al, 2000). The light/dark cycle is another method of synchronization that has commonly been used in photosynthetic organisms such as algae since the first publications describing synchronous culture of Chlorella (Tamiya et al, 1953) and Chlamydomonas (Bernstein, 1960).…”

Synchronous Growth and Plastid Replication in the Naturally Wall-less Alga Olisthodiscus luteus

“…Given this information, the synchronization index for an Olisthodiscus culture has been calculated to be 0.61. Although an ideal culture would have a synchronization index of 1, the value given for Olisthodiscus is quite acceptable when compared to that calculated for other synchronized systems (1,9,23).…”

“…The average number of chloroplasts found in an exponentially growing synchronous culture is rather stringently maintained at 20 to 21 plastids per cell, although a large variability in plastid complement (4- One of the first successful attempts to induce synchronous growth and cell division in a mass population of cells was reported in 1953 for the green alga Chlorella ellipsoidea (27). Since that time, a number of methods have been used to elicit a synchronous growth response in a variety of algal species includ-ing Euglena (20), Chlamydomonas (1), Scenedesmus (19), Gon-yaulax (26), and Navicula (17). The availability of these systems has allowed investigators to approach a large range of questions concerning the expression and control of specific morphological (2,4) and biochemical (7,13) events which take place during a normal cell cycle.…”

“…Olisthodiscus was axenically maintained in a defined artificial seawater medium which was developed from a growth medium (14) used for the culture of the red alga Porphyridium cruentum. This modified medium, designated 0-1, contains per liter of glass-distilled H20: 27 g of NaCl, 6.6 g of MgSO4-7H2O, 5.6 g of MgCl2* 6H2O, 1.5 g of CaCl2 -2H2O, 1.0 g of KNO3, 0.07 g of KH2PO4, 0.04 g of NaHCO3, 1 ml of stock solution A (18.6 g of Na2EDTA and 2.4 g of FeCl3 6H2O/liter, pH 7), 1 ml of stock solution B(40 mg of ZnCI2, 600 mg of H3BO3, 15 mg of CoCl2-6H2O, 40 mg of CuC12-2H2O, 488 mg of MnCl2A4H2O, and 37 mg of (NH4)6MoO24-4H2O per liter), 2.5 ml of 1 M trisHCl, pH 7.6, and 0.5 ml of vitamin stock solution (0.1 mg of biotin, 0.1 mg of B12, and 20 mg of thiamine-HCl made in a volume of 100 ml and stored frozen in small portions in screwcapped test tubes). A second growth medium designated 0-2, which has been routinely used for the growth of Olisthodiscus differs from 0-1 medium in that it contains only B12 as a vitamin source.…”

Characterization of the cell cycle in synchronous cultures of Chlamydomonas eugametos in relation to gametogenesis

“…The division cycle of Chlamydomonas can be synchronized by alternating light and dark periods (Bernstein, 1960;Surzycki, 1971 ;Lien & Knutsen, 1979;Spudich & Sager, 1980;Donnan et af., 1985 ;McAteer et al, 1985). Under these conditions, cells divide only during the dark period.…”