Fig. 5

Ultradian rhythms and caste-associated differential rhythmicity in gene expression. A Venn-diagrams showing the number of genes with significant ultradian expression in the ant brain, oscillating every 8-h (8 h-rhythms) and 12-h (12 h-rhythms); B Upset plot showing the number of genes uniquely expressed in, and shared between, diurnal (24 h) and ultradian (8 h and 12 h) gene sets. Each bar represents a unique intersection between the six diurnal and ultradian genesets (e.g., for-24: 24 h-oscillating genes in foragers, nur-12: 12 h-oscillating genes in nurses, etc.). A gene is binned only once, and as such, belongs to only one intersection. Dark circles indicate the gene sets that are part of a particular intersection. For example, the first circle indicates that there are 2543 genes that are uniquely cycling in foragers with a 24 h period (for-24). Similarly, the blue bar indicates that there are 291 genes that have a significantly diurnal expression in foragers but cycle every 8-h in nurses (for-24 h-nur-8 h); C Caste-associated differential rhythmicity in the expression of the core clock gene Period is shown. The expression of Per cycles every 24-h in forager brains (red) and every 8-h in nurses (blue); p-values obtained from eJTK are provided in parenthesis. The Zeitgeber Time is indicated on the x-axis, while the y-axis shows the normalized (Z-score) gene expression. The dark phase of the 12 h:12 h light–dark cycle is represented in grey (dark phase begins at ZT12); D Heatmap showing the daily expression of all genes in the for-24 h-nur-8 h geneset, for nurses and foragers. Caste identity is indicated above the heatmap as a column annotation (red-foragers and blue-nurses). The for-24 h-nur-8 h geneset was clustered into four groups, and the cluster identity of each gene is indicated as row annotations (“cluster”). The majority of 8 h-cycling genes in nurses, including the Per gene, belong to Cluster 1 and show a night-time peak in forager heads