[Cloning and expression of scavenger receptor class B BmSCRB8 in silkworm Bombyx mori]

Scavenger receptor class B is involved in various indispensable physiological processes, like the formation and inhibition of atherosclerosis or other cardiovascular diseases, innate immune defense and the removal of apoptotic cells. Here, we cloned BmSCRB8, a member of scavenger receptor class B in silkworm. We obtained the full-length cDNA sequence of BmSCRB8 by rapid amplification of cDNA ends (RACE), including 2 668 bp. The ORF of BmSCRB8 is 1 704 bp, encoding 567 amino acids. Online software prediction indicated that the molecular weight of BmSCRB8 is 63.87 kDa and the isoelectric point (pI) is 6.06. The space-time expression profile of BmSCRB8 was detected by reverse transcription PCR (RT-PCR), which implicated that BmSCRB8 is extensively expressed in each tissue and at each stage of blood. In addition, BmSCRB8 is highest expressed in fat body of silkworm, and is highly expressed in metamorphosis periods. Anti-BmSCRB8 polyclonal antibody was generated through prokaryotic expression, protein purification and mice immunization. Simultaneously, we constructed BmSCRB8 eukaryotic vector and then transfected embryonic cell line of silkworm. Immunofluorescence and overexpression showed that BmSCRB8 expressed specifically in membrane. Western blotting demonstrated that BmSCRB8 protein can be specifically recognized by anti-serum generated after mice immunization.