Skip to main content
. Author manuscript; available in PMC: 2019 Dec 13.
Published in final edited form as: Cell. 2018 Dec 13;175(7):1827–1841.e17. doi: 10.1016/j.cell.2018.11.032

Figure 1: Combination of physical and chemical signals triggers pup-directed aggression.

Figure 1:

(A) Images of real pup and four silicone pup decoys used in these experiments

(B) Raster plots of behaviors by virgin males (N = 19) presented with dummies swabbed with C57BL/6J salivary extract (top) or dead C57BL/6J pups (bottom). Red: aggressive encounters with biting, blue: chemo-investigative bouts.

(C) Total aggression per 5 min assay is significantly longer when males are exposed to dead pups compared to dummies (p < 0.001 by t-Test). N = 19.

(D) Latency to attack is significantly shorter when males are exposed to dead pups compared to dummies (p < 0.01 by t-Test). N = 19.

(E,F) Durations of aggressive interactions and all contacts in the initial 3 min of encounters in which males are presented with dummies swabbed with PBS (blue), pup salivary extracts (red) and adult male urine (yellow). *p < 0.05, **p < 0.01 by paired t-Test, N = 15. Connected circles represent data obtained with the same males.

(G) Sliding window analysis of aggressive interactions between males and dummies swabbed with various chemical cues. Top graph shows the cumulative duration of aggressive bouts in 2 min sliding windows. Bottom graph shows the p values of the paired t-Test for differences in aggressive bout durations between dummies swabbed with PBS and pup salivary extracts (blue) or between dummies swabbed with male urine and pup salivary extracts (brown) in 2 min sliding windows. N = 15.

(H) Raster plots of behaviors by virgin males exposed to various silicone dummies. Each event marks an interaction between males and the introduced pup decoy swabbed with pup salivary extract, with events categorized as aggressive (red) or non-aggressive (blue). N = 15.

(I) p-values of the paired t-Test for the differences in aggressive bout durations between decoys of various shapes swabbed with PBS and pup salivary extracts (blue) or between decoys swabbed with male urine and pup salivary extracts (brown) tested in 2 min sliding windows. Note the late attack against the “hybrid” decoy. N = 15.

(J) Cumulative aggression times by virgin males presented with pup decoys of four different shapes swabbed with pup salivary extract *p < 0.05, **p < 0.01, ***p < 0.001 by paired t-Test. N = 15.