Itoh Y, Arnold AP. Are females more variable than males in gene expression? Meta-analysis of microarray datasets.
Biol Sex Differ 2015;
6:18. [PMID:
26557976 PMCID:
PMC4640155 DOI:
10.1186/s13293-015-0036-8]
[Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Accepted: 09/11/2015] [Indexed: 01/02/2023] Open
Abstract
Background
The majority of preclinical biomedical research involves studies of males rather than females. It is thought that researchers have avoided females based on the idea that female traits are more variable than those of males because of cyclic variation in effects of ovarian hormones.
Methods
To test the assumption of inherently greater female variability, we analyzed 293 microarray datasets measuring gene expression in various tissues of mice and humans, comprising analysis of more than 5 million probes.
Results
Meta-analysis showed that on average, male gene expression is slightly more variable than that of females although the difference is small. We also tested if the X chromosome of humans shows greater variability in gene expression in males than in females, as might be expected because of hemizygous exposure of polymorphic X alleles but again found little sex difference.
Conclusion
Our analysis supports and extends previous studies reporting no overall greater phenotypic variability in females.
Electronic supplementary material
The online version of this article (doi:10.1186/s13293-015-0036-8) contains supplementary material, which is available to authorized users.
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