Sampling points for RNA-seq analysis and gene expression profiles during each molting process.

<p>(A) Caste differentiation observed in an incipient colony of <i>Zootermopsis nevadensis</i>. The oldest 3rd instar larva (No. 1 larva) molts into a presoldier, whereas the next-oldest 3rd instar larva (No. 2 larva) molts into the next instar (4th instar larva). Gut-purged individuals are always observed 3 days before the molts. Individuals were sampled at the following 5 developmental stages during each molt; pre-gut-purging (pGP), 0 days after gut-purging (GP0), 3 days after gut-purging (GP3), 0 days after the molt (M0) and 3 days after the molt (M3). (B) MDS plots of 14,204 genes detected by the RNA-seq data from the head during 3 molts in <i>Zootermopsis nevadensis</i>. (C) Numbers of caste-specific highly expressed genes among 3 timings in each molt (pGP, GP0, GP3). (D) Clusters of genes with highly expression levels in the head before the presoldier molt. Cluster 1 was composed of 54 genes showing no clear expression patterns with the molting events. Cluster 2 was composed of 26 genes with highly expression levels after the molt (M0) in each molting event. Cluster 3 and 4 were composed of 32 and 19 genes with highly expression levels before the molt (GP0 and GP3, respectively). The solid black line in each panel indicates the average expression pattern. The similarity was calculated based on the Jensen-Shannon distances using the RPKM (Reads Per Kilo base of exon model per Million mapped reads) values.