Hyd1 transcript levels and formate production increase under anaerobiosis. A, Hyd1 transcript levels in C. reinhardtii increased under anaerobic conditions as seen by RT-PCR of samples taken at 0, 0.5, 2, 4, and 8 h of argon gas bubbling. B, formate accumulated under continuous anaerobic conditions. Cell samples in the light were measured for formate levels after 0, 0.5, 2, 6, and 8 h of argon gas bubbling. Error bars indicate the standard deviation between measurements from two biological samples.