A Novel Gene Bombyx mori Carotenoid Oxygenases and Retinal Isomerase (BmCORI) Related to β-Carotene Depletion.

Carotenoids are the precursors of Vitamin A. They are cleaved by carotenoid oxygenase and then isomerized by retinoid isomerase. In this study, we identified a gene, Bombyx mori Carotenoid Oxygenases and Retinal Isomerase (BmCORI), which was the homolog of β-carotene 15,15'-monooxygenase and the retinal pigment epithelium protein of 65 kD. Further analysis indicated that the expression of BmCORI in silkworms was significantly higher in females than in males. We also found that the β-carotene content in BmCORI-expressed human embryonic kidney 293 cells was significantly lower than in the controls, while the lutein content showed a slight difference. These results suggested that BmCORI is related to carotenoid depletion, especially β-carotene depletion. Our research provides new insight into the study of BmCORI function.