Cry2, short for Cryptochrome 2, is a gene encoding a protein that functions as a blue-light photoreceptor in plants and as a core circadian clock regulator in mammals. In plants, it is involved in regulating diverse aspects of growth, while in mammals, it plays a role in circadian rhythms, DNA damage repair, and is related to certain disease-associated pathways [1,4-7].

In Arabidopsis, Cry2 affects the transcriptome even in darkness, suppressing cell division in the root apical meristem to inhibit root elongation [1]. In mice, missense mutations in Cry2 can suppress P53 and enhance cell growth, suggesting its role in cancer-related processes [3]. In 5xFAD mice, sleep deprivation upregulates Cry2 in the hippocampus, leading to synaptic dysfunction and cognitive decline [2]. Also, in adipocyte biology, Cry2 promotes adipogenesis by interacting with Per2 to repress transcription of Wnt pathway components [4,5].

In conclusion, Cry2 has diverse biological functions. In plants, it helps in coordinating growth in response to light and dark cues. In mammals, it is implicated in diseases such as cancer and neurodegenerative disorders like the cognitive decline in AD-related mouse models. The study of Cry2 in different genetic models, especially mouse models, has provided insights into its role in various biological processes and disease conditions.