Appendix 1—figure 10. Representative TEM images of Chlamydomonas strains, the parents (CC-1009 & CC-2343), as well as their progeny c1_1, c1_2, c1_3, c1_4, having been sparged with CO₂ for 30 seconds every hour during the night.

Under these conditions, both the strains in Panel A and B have not formed a pyrenoid starch sheath. Cells had been grown in steady state conditions in minimal 2NBH media, with 5 % CO₂ in air with 14:10 hour (light:dark) sinusoidal illumination with peak light intensity of 2000 μmoles m^–2 s^–1. Cells here were fixed two hours after dawn, at 7:00 am, when light levels were 825 μmoles m^–2 s^–1. Pyrenoids appeared absent or mostly unsheathed in these conditions. Scale bar = 2 μm.