dosage compensation

Dosage Compensation is the equalization of gene expression between the males and females of a species. Because sex chromosomes contain different numbers of genes, different species of organisms have developed different mechanisms to cope with this inequality. Replicating the actual gene is impossible; thus organisms instead equalize the expression from each gene. In humans, the females (XX) silence the transcription of one X chromosome of each pair, and transcribe all information from the other, expressed X chromosome. Thus, human females have the same number of expressed X-linked genes as do human males (XY), both genders having essentially one X chromosome per cell, from which to transcribe and express genes.