Mechanisms of Dosage Compensation in Animals

Table 3.3 Mechanisms of Dosage Compensation in Animals Animal Sex Chromosomes Dosage Compensation Mechanism Males Females Fruit f|y XY XX Expression of X-linked genes in males is doubled relative to female X-Iinked gene expression. Roundworm XO XXa Gene expression of each X chromosome in the hermaphrodite (”female”) is decreased to one-half that of the X chromosome in the male. Marsupial mammals XY XX The paternally derived X chromosome is inactivated in all female somatic cells. Placental mammals XY XX One X chromosome is randomly inactivated in each female somatic cell. a XX worms are hermaphrodites.