Temporal induction of Bombyx mori protein disulfide isomerase (bPDI) gene expression following infection. Total ribonucleic acid (RNA) extracted from the fat body of B mori infected with E coli for 0 hour (control, lane 1), 2 hours (lane 2), 4 hours (lane 3), 8 hours (lane 4), 16 hours (lane 5), and 24 hours (lane 6). Total RNA (5 μg each) per sample was transferred onto a Hybond-N nylon membrane and hybridized with a [α-32P]deoxyadenosine triphosphate–labeled bPDI complementary deoxyribonucleic acid as a probe. The bPDI band intensities were measured using ImageQuant software. The dot graph represents an average of 3 separate experiments. The inset shows the results from 1 representative experiment. 18S ribosomal RNA was used as a quantitation marker