Numbers of sex-specific genes and patterns of developmental regulation of adult sex-specific genes and adult sex-independent genes. Bar graphs present the number of genes that are either sex-specific in adult mouse liver or are up regulated (U), down regulated (D), or not significantly changed in expression (NC) from 3 wk to 8 wk or from 4 wk to 8 wk in male and female liver, as marked. A. The number of adult sex-specific genes increases from 3 to 8 wk, with onset of sex-specificity primarily occurring between 4 wk and 8 wk. B. Adult male-specific genes are predominantly up regulated in male liver, while in female liver they are mostly not regulated. C. Adult female-specific genes are primarily down regulated or are not regulated in male liver, while in female liver they are mostly not regulated. D. A somewhat greater number of adult sex-independent genes are regulated from 3 or 4 wk to 8 wk in male liver compared to female liver.