B. mori Host Response to Bb Figure 1. Phylogenetic tree of 16S rRNA sequences and survival curve of Bb infection the silkworm. (a) Phylogenetic tree with the sequences of 16S rRNA gene of Bb and its related species. Bb can produce spores and parasporal crystal. (b) Survival curve of Bb oral infection silkworm on day 3 of the fifth instar. Control 1: ddH2O feed silkworm rearing under the condition of temperature of 30uC and humidity of 90%. Control 2: ddH2O feed silkworm rearing under the condition of temperature of 25uC and humidity of 70%. Induced 1: Bb feed silkworm rearing under the condition of temperature of 30uC and humidity of 90%. Induced 2: Bb feed silkworm rearing under the condition of temperature of 25uC and humidity of 70%. (c) Natural infection and oral infection both can cause silkworm cuticle peutz. doi:10.1371/journal.pone.0008098.g001 PLoS ONE | www.plosone.org 3 December 2009 | Volume 4 | Issue 12 | e8098