Analysis of gene expression in the bacteriome tissue. As described in Materials and Methods, transcripts of candidate genes were quantitated by qRT-PCR in whole aposymbiotic fourth-instar larvae (control) and in bacteriomes dissected from symbiotic fourth-instar larvae. ESTs were classified according to sequence similarity as in Table 2. Each bar represents the mean of three independent measurements with standard error. The asterisk represents a significant (p < 0.05) difference between the bacteriome and the control, and a significantly high expression in a bacteriome is indicated by an arrow. ND, non-determined.