Figure 3.

In situ hybridization of Trp in eusocial hornet V. mandarinia adult worker brain. (A,B) Frontal section of the brain hemisphere hybridized with antisense (A) and sense (B) Trp probes. Trp signals scattered outside MBs are marked with arrowheads in (A). (C) Magnified view of the MB in a serial section of (A) and (B). (D) Illustration indicating the Trp signal strength and the calyx is overlaid to (C). Kenyon cells were divided into three regions based on the Trp signal intensity and the location of the somata: the Inner core (with moderate Trp signal, blue), middle (with weak Trp signal, yellow), and inner peripheral (with strong Trp signal, red) regions. The calyx is outlined with red line. (E) Distributions of the diameter of the somata of the each region are visualized with beanplot package⁶⁰. Weak, Moderate and Strong correspond to regions colored in yellow, blue and red in (D). MBC, mushroom body calyx; OL, optic lobe; AL, antennal lobe; “n = ”, number of the cells measured; asterisk, p-value < 0.01(Welch’s t-test for Moderate-Weak, Student’s t-test for Moderate-Strong). Bars indicate 500 μm in (A) and (B), 100 μm in (C) and (D).