Fig. 4. Unrooted neighbor-joining tree showing the relationships of representative vertebrate and invertebrate members of the insulin/insulin-like peptide family. Signal and C peptide sequences were removed from analysis. Numbers above the branches represent bootstrap support values >50%. The statistical significance of branch order was estimated by the generation of 10,000 replications of bootstrap resampling of the original aligned amino acid sequences.

Fig. 5. Expression of genes related to insulin signaling and AKH signaling in brains and abdomens of nurses and foragers. Data from these same four trials are pooled in Fig. 1A. Student's t test: *, P < 0.05; **, P < 0.01; ***, P < 0.001.

Fig. 6. Effects of diet on insulin-signaling gene expression and nutrient stores. (A and B) Data from the individual trials shown in A and B are pooled in Fig. 1B. (A) Expression of ilp1 in brains of 4-day-old bees and heads of 6-day-old bees fed pollen and sugar or sugar-only diet (individual trials) and of age-matched bees raised in a colony and of foragers. (B) Expression of inR1 in brains of 4- or 5-day-old bees fed pollen+sugar or sugar-only diet. (C) Abdominal lipid mass of 5-day-old caged bees fed pollen+sugar or sugar-only and of age-matched bees raised in a colony. (D) Effect of diet on abdominal vitellogenin (vg) expression in 4-day-old bees fed pollen+sugar or sugar-only diet. Student's t test: *, P < 0.05; **, P < 0.01; ***, P < 0.001.