bmo-let-7 expression profile in tissues from females and males of fifth-instar day-3 larvae. Eighteen tissues were harvested from females and males of day-3 5th instar larvae bred at 25°C and 85% H.R. The two antisense probes(anti-bmo-let-7 and anti-bmo-let-7*) were firstly hybridized on different blots, respectively, with equal amount of small RNAs on all loading wells. After stripping, exchanged the probe for the other blot. The candidate mature sequence is 22 nt or 23 nt, and the potential precursor is 72 nt or 87 nt long, but the precursor transcribed by silkworm genome can not be accumulated enough to be seen by Northern blotting. 5srRNA and U6 were used as the loading controls and levels of bmo-let-7 RNA are quantified relative to 5srRNA.