Fig. 1

Three-month-old Nell-1^+/6R mice presented abnormal behavioral patterns. A The grooming scores were assigned to 50 three-month-old Nell-1^+/6R mice (25 females and 25 males) with their fifty WT littermates (25 females and 25 males). No statistical significance was detected between genders of the Nell-1^+/6R mice. B Typical appearance of facial hair and whisker loss in the areas around the nose and eyes (for which a score “2” was assigned in panel A ) due to repetitive overgrooming behavior seen in the majority of Nell-1^+/6R mice. WT mouse without overgrooming issue (for which a score “0” was assigned in panel A ) was also shown for comparison. g.s. = grooming score. C A three-month-old Nell-1^+/6R mouse represented a large area of facial hair loss due to overgrooming (for which a score “3” was assigned in panel A ). D A three-month-old Nell-1^+/6R mouse represented full body hair loss due to overgrooming (for which a score “4” was assigned in panel A). E Both male and female Nell-1^+/6R  mice represented an increased number of buried marbles comparing to their WT littermates during a 10-minute marble-burying test. Data are presented as a median ± 95% confidence interval, n  = 15 for each group. F Nell-1^+/6R  mice represented social behavior abnormalities in the three-chamber social interaction test. The time interacting with either an unfamiliar WT mouse (mouse cup) or an inanimate object (empty cup) in 10 min was shown in the figure in the format of the percentage of total testing time. Data are presented as median ± 95% confidence interval; n  = 12 (female) or 16 (male) for each genotype, respectively. Mann-Whitney U test was used for statistical analysis. N.S. none statistically significant. *: P  < 0.05; ***: P  < 0.005