RRC ID 35977
Author Nozawa M, Fukuda N, Ikeo K, Gojobori T.
Title Tissue- and stage-dependent dosage compensation on the neo-X chromosome in Drosophila pseudoobscura.
Journal Mol Biol Evol
Abstract Sex chromosome dosage compensation (DC) is widely accepted in various organisms. This concept is mostly supported by comparisons of gene expression between chromosomes and between sexes. However, genes on the X chromosome and autosomes are mostly not homologous, and the average gene expression level on these chromosomes may not be the same even under DC, which complicates comparisons between chromosomes. Many genes with sex-biased expression also make comparisons between sexes difficult. To overcome these issues, we investigated DC by comparing the expression of neo-X-linked genes in Drosophila pseudoobscura with those of their autosomal orthologs in other Drosophila species. The ratio of the former to the latter in males would be 1 under DC, whereas it becomes 0.5 without DC. We found that the ratio was ∼0.85 for adult whole bodies, indicating that the DC is incomplete on the neo-X chromosome in adults as a whole. The ratio (∼0.90) was also significantly less than 1 for adult bodies without gonads, whereas it was ∼1.0 for adult heads. These results indicate that DC varies among tissues. Our sliding-window analysis of the ratio also revealed that the upregulation of neo-X-linked genes in males occurred chromosome wide in all tissues analyzed, indicating global upregulation mechanisms. However, we found that gene functions also affected the levels of DC. Furthermore, most of the genes recently moved to the X were already under DC at the larval stage but not at the adult stage. These results suggest that DC in Drosophila species operates in a tissue/stage-dependent manner.
Volume 31(3)
Pages 614-24
Published 2014-3-1
DOI 10.1093/molbev/mst239
PII mst239
PMID 24307686
MeSH Animals Chromosomes, Insect / genetics* Dosage Compensation, Genetic* Drosophila / genetics* Drosophila / growth & development* Female Genes, Insect / genetics Larva / genetics Life Cycle Stages / genetics* Male Organ Specificity / genetics* X Chromosome / genetics*
IF 11.062
Times Cited 14
WOS Category GENETICS & HEREDITY BIOCHEMISTRY & MOLECULAR BIOLOGY EVOLUTIONARY BIOLOGY
Resource
Drosophila D. pseudoobscura (K-s12) D. persimilis (K-s11) D. simulans (K-s05) and D. sechellia (K-s10)