Large-scale population study of human cell lines indicates that dosage compensation is virtually complete.
X chromosome inactivation in female mammals results in dosage compensation of X-linked gene products between the sexes. In humans there is evidence that a substantial proportion of genes escape from silencing. We have carried out a large-scale analysis of gene expression in lymphoblastoid cell lines from four human populations to determine the extent to which escape from X chromosome inactivation disrupts dosage compensation. We conclude that dosage compensation is virtually complete. Overall expression from the X chromosome is only slightly higher in females and can largely be accounted for by elevated female expression of approximately 5% of X-linked genes. We suggest that the potential contribution of escape from X chromosome inactivation to phenotypic differences between the sexes is more limited than previously believed.
Johnston
Colette M
CM
X Chromosome Group, Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, United Kingdom.
Lovell
Frances L
FL
Leongamornlert
Daniel A
DA
Stranger
Barbara E
BE
Dermitzakis
Emmanouil T
ET
Ross
Mark T
MT
D002460:Cell Line; D041321:Chromosomes, Human, X; D041322:Chromosomes, Human, Y; D004303:Dosage Compensation, Genetic; D005260:Female; D015870:Gene Expression; D050172:Genes, X-Linked; D005828:Genetics, Population; D006239:Haplotypes; D006579:Heterozygote; D006801:Humans; D008214:Lymphocytes / Q000166:cytology*; D008297:Male; D020411:Oligonucleotide Array Sequence Analysis; D020641:Polymorphism, Single Nucleotide; D049951:X Chromosome Inactivation