Fig 2.

Quantitative RT-PCR analysis of gene expression in weevil bacteriomes at different developmental stages. Expression of invA, spaPQ, and fusA was analyzed for three individual cohorts of reproductively synchronized animals at 3-day intervals through the course of their development into adulthood. To calculate relative transcript numbers, standard curves were generated for each gene by serially diluting RNA templates with the highest transcript numbers for each gene. “Fold-difference” values were determined by comparing transcript numbers in each sample to a control sample, defined within each cohort as the sample with the lowest number of transcripts for a given gene. Peak levels of the invA and spaPQ transcripts are detected in weevils undertaking pupation and metamorphosis, whereas levels of the housekeeping gene (fusA) transcripts remain constant throughout weevil development.