Molecular Cloning and Expression of a Cryptochrome Gene CiCRY-DASH1 from the Antarctic microalga Chlamydomonas sp. ICE-L.

Cryptochromes (CRYs) are flavin-binding proteins that sense blue and near-ultraviolet light and participate in the photoreactions of organisms and the regulation of biological clocks. In this study, the complete open reading frame (ORF) of CiCRY-DASH1 (GenBank ID MK392361), encoding one kind of cryptochrome, was cloned from the Antarctic microalga Chlamydomonas sp. ICE-L. The quantitative real-time PCR study showed that the CiCRY-DASH1 had the highest expression at 5 °C and salinity of 32‰. The CiCRY-DASH1 was positively regulated by blue, yellow, or red light. Moreover, the CiCRY-DASH1 can positively respond to extreme polar day and night treatment and exhibit a certain circadian rhythm, which indicated that CiCRY-DASH1 participated in the circadian clock and its expression was regulated by circadian rhythms. And the CiCRY-DASH1 was more noticeably affected by ultraviolet-B radiation than ultraviolet-A radiation, indicating ultraviolet-B light does obvious damage to Antarctic microalgae.