Data set for "Synechocystis sp. PCC 6803 shows high cell cycle dynamics reflected by an extraordinary genome copy number variation"

The uploaded files contain (1) data on the growth analysis (OD750 and growth rate) of Synechocystis sp. PCC 6803 strains grown under various conditions, (2) calculations of genome copy numbers obtained from quantitative PCR results as well as (3) electron microscope pictures of two subpopulations of Synechocystis sp. PCC 6803 cells formed after continuous phosphorus starvation. 1) Time course experiments were performed under 8 different growth conditions varying three parameters, i.e., low and high light intensity (50 and 200 µmol photons m-2 s-1, LL and HL), low and high CO2 concentration (ambient CO2 and 2% CO2, LC and HC), and high and low phosphate concentration (yBG11 medium containing the usual high 175 µM and low 17.5 µM phosphate, HP and LP), respectively. This resulted in the following 8 conditions: LL-LC-HP, HL-LC-HP, LL-HC-HP, HL-HC-HP, LL-LC-LP, HL-LC-LP, LL-HC-LP, HL-HC-LP. Cultivation at HL-HC and LL-HC conditions were performed in 1L flasks for 7 and 14 days, respectively. Cultivation at LL-LC was performed in 1L-flasks and 250 ml-flasks for 35 and 21 days, respectively. Cultivation at HL-LC was also performed in both culture scale formats for 8 and 21 days, respectively. Growth was continuously analysed by measurement of OD750 and the growth rates µ (1/h) were calculated for the respective time intervals. The file “OD750 and growth rate” includes mean OD750–values and growth rates +/- SDEV as well as exact specifications on the applied parameters for all cultivation conditions. 2) For analysis of the genome copy number (GCN), Synechocystis sp. PCC 6803 was cultivated at HL-HC-HP and HL-HC-LP conditions and samples were prepared 1, 2, 3 and 7 days after inoculation. Chromosomal DNA was extracted and analysed by quantitative PCR (qPCR). GCNs were calculated from biological duplicates, technical triplicates and four different concentrations of the applied DNA samples. The file “qPCR HL-HC.xlsx” includes the mean GCNs +/- SDEV (qPCR overview), the corresponding calculations as well as descriptions of the applied method and cultivation conditions. 3) For microscopy analysis of the two subpopulations of Synechocystis sp. PCC 6803 differing in cell size and properties, cultures were grown at HL-HC-LP conditions for 7 days. 107 cells of population 1 (P1, large cells) and population 2 (P2, small cells) were live cell sorted in a BD Influx v7 Sorter according to their size (FSC) and phycobillin autofluorescence (616/23 [488]), fixed and prepared for microscopy. In addition, 107 unsorted cells containing both cell-types (mix) were prepared as a control. Analysis of the three samples (P1, P2 and mix) was performed via Helium ion microscopy (HIM) and Scanning electron microscopy in transmission mode (STEM). The respective files “HIM.zip” and “STEM.zip” contain microscopy pictures of the respective samples as well as a method-file (including background information on the 2 cellular subpopulations and descriptions of the applied method). Graphical illustrations of the results are presented in the publication “Synechocystis sp. PCC 6803 shows high cell cycle dynamics reflected by an extraordinary genome copy number variation".