Evidence for compensatory upregulation of expressed X-linked genes in mammals, Caenorhabditis elegans and Drosophila melanogaster.
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.
Department of Pathology, University of Washington School of Medicine, Seattle, USA.
Xinxian
X
Deng
Joseph B
JB
Hiatt
Di Kim
DK
Nguyen
Sevinc
S
Ercan
David
D
Sturgill
LaDeana W
LW
Hillier
Felix
F
Schlesinger
Carrie A
CA
Davis
Valerie J
VJ
Reinke
Thomas R
TR
Gingeras
Jay
J
Shendure
Robert H
RH
Waterston
Brian
B
Oliver
Jason D
JD
Lieb
Christine M
CM
Disteche
D000818:Animals; D017173:Caenorhabditis elegans / Q000235:genetics*; D002460:Cell Line; D004303:Dosage Compensation, Genetic; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism; D004331:Drosophila melanogaster / Q000235:genetics*; D005260:Female; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D050172:Genes, X-Linked; D006801:Humans; D008297:Male; D051379:Mice; D020411:Oligonucleotide Array Sequence Analysis; D009928:Organ Specificity; D010053:Ovary / Q000378:metabolism; D012319:RNA Polymerase II / Q000378:metabolism; D013737:Testis / Q000378:metabolism; D014158:Transcription, Genetic; D015854:Up-Regulation; D014960:X Chromosome / Q000235:genetics
D029721:Drosophila Proteins; C091674:bam protein, Drosophila; D012319:RNA Polymerase II