Fig. 2: Sex differences in social interaction of cHET mice.

a Schematic of the three-chamber social interaction (3CSI) test and representative heatmap illustrating zone preference (left). Both group-housed and socially isolated male mice spent significantly more time in the interaction zone with a novel male conspecific compared to an inanimate object (right), indicating preserved social preference. b All male groups, including WT and cHET mice, demonstrated robust sociability in the 3CSI assay. Sociability index ≥ 0.5 signifies social preference. c In the dyadic social interaction test, socially isolated cHET males exhibited increased affiliative behaviors—spending more time investigating (sniffing and grooming) the unfamiliar male—compared to WT controls (left). No differences were observed in the number of aggressive bouts between genotypes (right). d Socially isolated cHET males exhibited normal mating behavior, with comparable investigation times and mounting durations toward sexually receptive female conspecifics relative to WT controls. e Schematic of the 3CSI test for female cohorts and representative heatmaps of interaction patterns (left). While group-housed female cHET mice displayed normal social preference, socially isolated female cHETs showed reduced interaction with the unfamiliar female, favoring the object zone (right). f A significant reduction in social preference is observed in socially isolated cHET females, indicative of stress-induced social deficits. Sociability index ≥ 0.5 signifies social preference. Statistical tests: a, b, e, f Two-way ANOVA with Bonferroni post-hoc test; c, d Mann-Whitney test. *p < 0.05, **p < 0.01, ****p < 0.001, ns not significant. Sample size: n = 7–15 mice/ group.