Fig. 4. Modulation of social hierarchy by PAS1s from various amniotes in caged adult male mice.
a Schematic of the social dominance tube test. b Winning rate of PAS1w/m male mice against PAS1w/w male mice. The x-axis indicates the number of adult male mice in each cage with the two different genotypes (PAS1w/m: PAS1w/w). c Winning rate of PAS1c/m male mice against PAS1c/c male mice. The x-axis indicates the number of adult male mice in each cage with the two different genotypes (PAS1c/m: PAS1c/c). d Results of the tube test over 7 consecutive days. e Proposed mechanism for positive selection on PAS1 and the evolution of social hierarchy. A beneficial allele (denoted “A”) occurs at the PAS1 locus, leading to a beneficial change in the expression of Lhx2. Allele “a” represents the ancestral allele. The genotype of the carrier with the beneficial allele is designated as “Aa”. The frequency of the beneficial allele is low in the beginning phase of positive selection.81