Abstract

In the present study, using a BV/PH-Bms3a-EGFP, we found that Bombyx moriribosomal protein S3a (BmS3a) with EGFP fused to its C-terminal, was predominantly localized in the cytoplasm of B. mori cells. Subsequently, to investigate the effect of BmS3a over-expression on BmNPV infection both at the cellular level and in vivo, a transgenic BmN cell line expressing BmS3a was constructed using a piggybac-A3-EGFP and recombinant baculovirues expressing BmS3a-EGFP fusion protein (BV/IE1-Bms3a-EGFP) or EGFP (BV/EGFP) were produced using BmNPV/Bac-to-Bac expression system. Results showed that the number of polyhedral in the transgenic cells of BmS3a was much smaller than that in non-transgenic cells, and that silkworms injected with BV/IE1-Bms3a-EGFP survived much longer than those injected with BV/ EGFP. Taken together, we speculated that BmS3a might be capable of inhibiting BmNPV replication through its activities in the cytoplasm.

Key words: BmS3a, subcellular localization, over-expression, effect.

Abbreviation

FDD, Fluorescent differential display; Fte-1, v-fos transformation effector; BmNPV, Bombyx mori nuclear polyhedrosis virus; NB, resistant silkworm strain; 306, highly susceptible silkworm strain; 306NNZZ, near isogenic line;Bms3a, Bombyx mori S3a; BmN cell,  Bombyx mori cell line; QRT-PCR,quantitative reverse transcriptase-polymerase chain reaction; FBS, fetal calf serum;pSK, pBluescript II SK (+);PBS,  phosphate-buffered saline; SDS-PAGE, sodium dodecyl sulfate polyacrylamide gel electrophoresis.