Abstract

This is the first identification of a gene encoding Bm-LOC778477 protein (a “hypothetical protein”) from silkworm pupal cDNA library. The full-length Bm-LOC778477 cDNA contained a 546-bp ORF encoding 187 amino acids. Using bioinformatics, the Bm-LOC778477 gene was predicted on the W chromosome and 4 exons and 3 introns were determined when compared to the silkworm genome. The consensus splice sites of exon/intron junctions were consistent with Chambon′s rule. In addition, TATA box and initiator (Inr) were also predicated in the promoter region of the gene. To elucidate whether Bm-LOC778477 gene encoded a functional protein in silkworm, pGEX-4T-1-Bm-LOC778477 expression plasmid was constructed to express GST-LOC778477 fusion protein in Escherichia coli Rosetta. rBm-LOC778477 was used to generate anti- Bm-LOC778477 polyclonal antibody, which were used to determine the subcellular localization of Bm-LOC778477. Immunostaining indicated that Bm-LOC778477 protein could be found in both the cytoplasm and nucleus. Western blot analysis indicated that Bm-LOC778477 was specific expression during the pupa stage and there was seldom expression during the larvae stage. Therefore, we propose that Bm-LOC778477 may play an important role during pupa stage development. These results may lay an important foundation of further function studies of Bm-LOC778477 protein.

Key words: Bm-LOC778477, hypothetical protein, subcellular localization