Inhibition of Expression of the Circadian Clock Gene Cryptochrome 1 Causes Abnormal Glucometabolic and Cell Growth in Bombyx mori Cells

Abstract

Cryptochrome is the earliest discovered photoreceptor protein in organisms. However, the effect of CRY (BmCRY), the clock protein in Bombyx mori, on the body or cell metabolism remains unclear. In this study, we continuously interfered with the expression of the BmCry1 gene (Cry1-KD) in the silkworm ovary cell line (BmN), and the BmN cells developed abnormally, with accelerated cell growth and a smaller nucleus. Metabolomics was used to identify the cause of the abnormal development of Cry1-KD cells based on gas chromatography/liquid chromatography-mass spectrometry. A total of 56 differential metabolites including sugars, acids, amino acids, and nucleotides were identified in wild-type and Cry1-KD cells. KEGG enrichment analysis showed that BmCry1 knockdown resulted in significantly upregulated glycometabolism in BmN cells, indicated by glucose-6-phosphate, fructose-6-phosphate, and pyruvic acid levels. The activities of key enzymes BmHK, BmPFK, and BmPK as well as their mRNA levels further confirmed that the glycometabolism level of Cry1-KD cells was significantly increased. Our results show that a possible mechanism of BmCry1 knockdown leading to abnormal cell development is the elevated level of glucose metabolism in cells.

Knockout ofcryptochrome 1disrupts circadian rhythm and photoperiodic diapause induction in the silkworm,Bombyx mori

“…Furthermore, Homma et al, (2022), having knocked out not only per , tim , Clk and cyc but also cry1 and cry2 , reported effects on temperature-dependent diapause induction, finding disruption in cry2 but not cry1 knockout. In recent years, studies using the cry1 knockout strain have revealed cry1 ’s role in hatching rhythm, immunity, cell growth, and hormonal control of development (Qiu et al, 2022, 2023a, 2023b; Yuan et al, 2023). However, the involvement of cry genes in B. mori photoperiodism remains unclear.…”