Figure 10: Silk gland of a transgenic silkworm with a fibroin H chain-EGFP fusion gene. M, MSG; P, PSG. The image was taken with a fluorescence microscope equipped with a GFP filter. The fusion protein, which comprises the fibroin H N-terminal region, EGFP, and the fibroin C-terminal region, is produced in the PSG and accumulates in the lumen of the MSG. Therefore, very strong fluorescence is observed in the MSG.