The E(spl)m gamma gene in Drosophila is a regulatory target gene downstream of the Notch pathway. BmE(spl)m gamma (Bombyx mori, E(spl)m gamma) is an ortholog of the Drosophila E(spl)m gamma gene, and the gene encodes a protein with 248 amino acid residues. This gene was cloned and overexpressed in Escherichia coli BL21(DE3). The recombinant protein was purified and subsequently used to generate a rabbit polyclonal antibody. Western blotting analyses showed that BmE(spl)m gamma expression is high in pupa and egg, and low in larva and moth. In the fifth instar larva, the protein levels are high in head, epidermis, sexual gland, trachea, and the fatbody and low in the Malpighian tubule, hemolymph, gut, and silk gland. The further immunohistochemical analyses also showed higher BmE(spl)m gamma expression in the head of fifth instar larva and pupa. Of the four moth parts studied, the thorax had the highest expression level. Thus, BmE(spl)m gamma might be associated with neurogenesis in silkworm. Furthermore, DAPT (a gamma-secretase inhibitor and an indirect inhibitor of Notch) blocking experiments showed that higher concentrations of the blocking agent and a longer processing time reduce the transcription levels of the BmE(spl)m gamma gene, demonstrating that the silkworm BmE(spl)m gamma gene is associated with the Notch signal pathway. These findings suggest that the function of BmE(spl)m gamma may be similar to that of its Drosophila homolog.