Integration of Light Signals by the Retinoblastoma Pathway in the Control of S Phase Entry in the Picophytoplanktonic Cell Ostreococcus
Figure 5
Differential regulation of CyclinA transcription and protein accumulation during commitment.
Cells were grown in LD 12, 12 at 35 µmol quanta.m−2.sec−1 for 5 days and then exposed to light of 100 µmol quanta.m−2.sec−1 for 8 hours (A) or 3 hours (B). CyclinA mRNA levels were monitored by real time RT-PCR (filled inverted triangles) and CyclinA-Luc protein accumulation by luciferase assay (open inverted triangle). (C) and (D) Cells were grown in LD 12, 12 at 35 µmol quanta.m−2.sec−1 for 5 days and then exposed to 12 hours of light at various intensities from 8 to 150 µmol quanta.m−2.sec−1 as described in Figure 1 (corresponding colour codes). CyclinA transcription profiles were similar in all conditions (C). In contrast CyclinA-Luc protein was detected later when lowering light intensity (D). RLU: relative luminescence unit on the Y axis.