Points of commitment to reproductive events as a tool for analysis of the cell cycle in synchronous cultures of algae

Vítová, Milada; Zachleder, Vilém

doi:10.1007/bf02931463

Cited by 25 publications

(20 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, if growth continues during the post-commitment phase, the cells can attain one or more additional CPs consecutively. At each of the CPs, the processes are triggered, leading, after a certain time interval, to initiation of the round(s) of DNA replication(s), nuclear division(s), cytokinesis and finally a release of newly formed daughter cells (Š etlík et al 1972;Zachleder and Š etlík 1990;Zachleder et al 1997;Vítová and Zachleder 2005).…”

Section: Introductionmentioning

confidence: 99%

Chlamydomonas reinhardtii: duration of its cell cycle and phases at growth rates affected by light intensity

Vítová

Bišová

Umysová

et al. 2010

Planta

View full text Add to dashboard Cite

In the cultures of the alga Chlamydomonas reinhardtii, division rhythms of any length from 12 to 75 h were found at a range of different growth rates that were set by the intensity of light as the sole source of energy. The responses to light intensity differed in terms of altered duration of the phase from the beginning of the cell cycle to the commitment to divide, and of the phase after commitment to cell division. The duration of the pre-commitment phase was determined by the time required to attain critical cell size and sufficient energy reserves (starch), and thus was inversely proportional to growth rate. If growth was stopped by interposing a period of darkness, the pre-commitment phase was prolonged corresponding to the duration of the dark interval. The duration of the post-commitment phase, during which the processes leading to cell division occurred, was constant and independent of growth rate (light intensity) in the cells of the same division number, or prolonged with increasing division number. It appeared that different regulatory mechanisms operated through these two phases, both of which were inconsistent with gating of cell division at any constant time interval. No evidence was found to support any hypothetical timer, suggested to be triggered at the time of daughter cell release.

show abstract

Section: Introductionmentioning

confidence: 99%

Chlamydomonas reinhardtii: duration of its cell cycle and phases at growth rates affected by light intensity

Vítová

Bišová

Umysová

et al. 2010

Planta

View full text Add to dashboard Cite

show abstract

“…In contrast, in synchronized cultures of Chlamydomonas eugametos (Zachleder and van den Ende 1992), Scenedesmus armatus (Tukaj et al 1996), Scenedesmus quadricauda (Zachleder et al , 2002Ketlík and Zachleder 1984;Cepák and Zachleder 1988;Zachleder and Ketlík 1990;Vítová and Zachleder 2005), the length of the pre-commitment period was found to depend only on the rate of growth at a given light intensity and temperature, excluding the role of a timer. A similar result was also reported recently for rat Wbroblasts (Yeom et al 2010).…”

Section: Introductionmentioning

confidence: 99%

“…While the eVect of light intensity on the duration of the cell cycle and its phases has been examined extensively in autotrophic algae (Wanka 1959(Wanka , 1968Pirson et al 1963;Ketlík et al 1972;Zachleder et al 1975Zachleder et al , 2002Zachleder and Ketlík 1982;Zachleder and van den Ende 1992;Vítová and Zachleder 2005), studies on the eVects of temperature are less intensive (Morimura 1959;Ketlík et al 1975;Donnan and John 1984;Donnan et al 1985) and data interpretations are controversial (McAteer et al 1985;Zachleder and van den Ende 1992;Goto and Johnson 1995;Vítová et al 2011).…”

Section: Introductionmentioning

confidence: 99%

Chlamydomonas reinhardtii: duration of its cell cycle and phases at growth rates affected by temperature

Vítová

Bišová

Hlavová

et al. 2011

Planta

View full text Add to dashboard Cite

Synchronized cultures of the green alga Chlamydomonas reinhardtii were grown photoautotrophically under a wide range of environmental conditions including temperature (15-37 °C), different mean light intensities (132, 150, 264 μmol m⁻² s⁻¹), different illumination regimes (continuous illumination or alternation of light/dark periods of different durations), and culture methods (batch or continuous culture regimes). These variable experimental approaches were chosen in order to assess the role of temperature in the timing of cell division, the length of the cell cycle and its pre- and post-commitment phases. Analysis of the effect of temperature, from 15 to 37 °C, on synchronized cultures showed that the length of the cell cycle varied markedly from times as short as 14 h to as long as 36 h. We have shown that the length of the cell cycle was proportional to growth rate under any given combination of growth conditions. These findings were supported by the determination of the temperature coefficient (Q₁₀), whose values were above the level expected for temperature-compensated processes. The data presented here show that cell cycle duration in C. reinhardtii is a function of growth rate and is not controlled by a temperature independent endogenous timer or oscillator, including a circadian one.

show abstract

“…In case of multiple divisions, cells attain n consecutive CPs resulting in n overlapping reproductive sequences. These defined points in the cell cycle, whose attainment reports on competence for division, are generally considered to be cell-cycle control points for entering the division phase (Spudich & Sager 1980;Donnan & John 1983;Zachleder & van den Ende 1992;Vítová & Zachleder 2005). The first commitment point reached is equivalent to the start point in budding yeast and the restriction point in mammalian cells (John 1984).…”

Section: Chlamydomonas Reinhardtii Cell Cyclementioning

confidence: 99%

Use of algae in the study of essential cell processes

et al. 2008

View full text Add to dashboard Cite

Maintenance of genomic stability is of crucial importance for all living organisms. It is no surprise that during evolution, a series of highly selective and efficient systems to detect DNA damage and control its repair have evolved. To this end, signal transduction pathways are involved in pausing the cell division cycle to provide time for repair, and ultimately releasing the cell cycle from arrest. Genetic components of the damage and replication checkpoints have been identified and a working model is beginning to emerge. This area of biological inquiry has received a great deal of attention in the past decade with the realization that the underlying regulatory mechanisms controlling the cell cycle are conserved throughout eukaryotic evolution. Many of the key players in this response have structural and functional counterparts in species as diverse as yeast and human. In recent years attention has also been paid to the plant kingdom suggesting that checkpoint controls have been highly conserved during evolution. The unicellular green alga Chlamydomonas reinhardtii is a suitable model organism for the study of basic cellular processes including cell cycle regulation and DNA repair. To investigate how algal cells accomplish these tasks, we have isolated mutants in the recognition and repair of DNA damage or in the response to DNA damage.

show abstract

Points of commitment to reproductive events as a tool for analysis of the cell cycle in synchronous cultures of algae

Cited by 25 publications

References 30 publications

Chlamydomonas reinhardtii: duration of its cell cycle and phases at growth rates affected by light intensity

Chlamydomonas reinhardtii: duration of its cell cycle and phases at growth rates affected by light intensity

Chlamydomonas reinhardtii: duration of its cell cycle and phases at growth rates affected by temperature

Use of algae in the study of essential cell processes

Contact Info

Product

Resources

About