Sex-biased gene expression and evolution of the X chromosome in nematodes

Sarah Elizabeth Albritton, Anna Lena Kranz, Prashant Rao, Maxwell Kramer, Christoph Dieterich, Sevinç Ercan

Research output: Contribution to journalArticle

Abstract

Studies of X chromosome evolution in various organisms have indicated that sex-biased genes are nonrandomly distributed between the X and autosomes. Here, to extend these studies to nematodes, we annotated and analyzed X chromosome gene content in four Caenorhabditis species and in Pristionchus pacificus. Our gene expression analyses comparing young adult male and female mRNA-seq data indicate that, in general, nematode X chromosomes are enriched for genes with high female-biased expression and depleted of genes with high male-biased expression. Genes with low sex-biased expression do not show the same trend of X chromosome enrichment and depletion. Combined with the observation that highly sex-biased genes are primarily expressed in the gonad, differential distribution of sex-biased genes reflects differences in evolutionary pressures linked to tissue-specific regulation of X chromosome transcription. Our data also indicate that X dosage imbalance between males (XO) and females (XX) is influential in shaping both expression and gene content of the X chromosome. Predicted upregulation of the single male X to match autosomal transcription (Ohno's hypothesis) is supported by our observation that overall transcript levels from the X and autosomes are similar for highly expressed genes. However, comparison of differentially located one-to-one orthologs between C. elegans and P. pacificus indicates lower expression of X-linked orthologs, arguing against X upregulation. These contradicting observations may be reconciled if X upregulation is not a global mechanism but instead acts locally on a subset of tissues and X-linked genes that are dosage sensitive.

Original languageEnglish (US)
Pages (from-to)865-883
Number of pages19
JournalGenetics
Volume197
Issue number3
DOIs
StatePublished - 2014

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X Chromosome
X-Linked Genes
Gene Expression
Up-Regulation
Genes
Caenorhabditis
Sex Distribution
Gene Dosage
Gonads
Young Adult
Pressure
Messenger RNA

ASJC Scopus subject areas

  • Genetics

Cite this

Albritton, S. E., Kranz, A. L., Rao, P., Kramer, M., Dieterich, C., & Ercan, S. (2014). Sex-biased gene expression and evolution of the X chromosome in nematodes. Genetics, 197(3), 865-883. https://doi.org/10.1534/genetics.114.163311

Sex-biased gene expression and evolution of the X chromosome in nematodes. / Albritton, Sarah Elizabeth; Kranz, Anna Lena; Rao, Prashant; Kramer, Maxwell; Dieterich, Christoph; Ercan, Sevinç.

In: Genetics, Vol. 197, No. 3, 2014, p. 865-883.

Research output: Contribution to journalArticle

Albritton, SE, Kranz, AL, Rao, P, Kramer, M, Dieterich, C & Ercan, S 2014, 'Sex-biased gene expression and evolution of the X chromosome in nematodes', Genetics, vol. 197, no. 3, pp. 865-883. https://doi.org/10.1534/genetics.114.163311
Albritton, Sarah Elizabeth ; Kranz, Anna Lena ; Rao, Prashant ; Kramer, Maxwell ; Dieterich, Christoph ; Ercan, Sevinç. / Sex-biased gene expression and evolution of the X chromosome in nematodes. In: Genetics. 2014 ; Vol. 197, No. 3. pp. 865-883.
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