Experimental series.

<p>In Experiment 1 (a), <i>P</i>. <i>tricornutum</i> cells acclimated to a 12h light: 12h dark (L/D) photoperiod at 200μE m⁻² s⁻¹ (₂₀₀L/D) were transferred to continuous light (L/L) of the same intensity (₂₀₀L/L). In Experiment 2 (b), culture acclimated to a 12h light: 12h dark photoperiod at 1200μE m⁻² s⁻¹ (₁₂₀₀L/D) was shifted to 50μE m⁻² s⁻¹ on the same photoperiod (₅₀L/D). In Experiment 1, samples were collected at hours 2, 7, and 11 of each 12h phase (thus in each light phase at L2, L7, and L11; in each dark phase at D2, D7, and D11; and in each subjective dark phase at sD2, sD7, and sD11). In Experiment 2, samples were collected at hours L2, L7, L11, and D11. The subscripted number after L or D indicates the 24h photoperiod during which that sample was collected (e.g., D₂7 is the seventh hour of the dark phase pertaining to the second photoperiod of that experiment).