Deng, X., Hiatt, J.B., Nguyen, D.K., Ercan, S., Sturgill, D., Hillier, L.W., Schlesinger, F., Davis, C.A., Reinke, V.J., Gingeras, T.R., Shendure, J., Waterston, R.H., Oliver, B., Lieb, J.D., Disteche, C.M. (2011). Evidence for compensatory upregulation of expressed X-linked genes in mammals, Caenorhabditis elegans and Drosophila melanogaster.  Nat. Genet. 43(12): 1179--1185.

FBrf0216749

Research paper

Many animal species use a chromosome-based mechanism of sex determination, which has led to the coordinate evolution of dosage-compensation systems. Dosage compensation not only corrects the imbalance in the number of X chromosomes between the sexes but also is hypothesized to correct dosage imbalance within cells that is due to monoallelic X-linked expression and biallelic autosomal expression, by upregulating X-linked genes twofold (termed 'Ohno's hypothesis'). Although this hypothesis is well supported by expression analyses of individual X-linked genes and by microarray-based transcriptome analyses, it was challenged by a recent study using RNA sequencing and proteomics. We obtained new, independent RNA-seq data, measured RNA polymerase distribution and reanalyzed published expression data in mammals, C. elegans and Drosophila. Our analyses, which take into account the skewed gene content of the X chromosome, support the hypothesis of upregulation of expressed X-linked genes to balance expression of the genome.

PMC3576853 (PMC) (EuropePMC)