Impact of Filtering Methods on X-Chromosome Dosage Compensation Analysis
Author Information
Author(s): Raphaële Castagné, Maxime Rotival, Tanja Zeller, Philipp S. Wild, Vinh Truong, David-Alexandre Trégouët, Thomas Munzel, Andreas Ziegler, François Cambien, Stefan Blankenberg, Laurence Tiret
Primary Institution: INSERM UMRS 937, Pierre and Marie Curie University (UPMC, Paris 6) and Medical School, Paris, France
Hypothesis
Does the choice of filtering method in microarray studies affect the inference regarding dosage compensation of the active X-chromosome?
Conclusion
The method used for filtering lowly expressed genes in microarrays significantly impacts the conclusions about dosage compensation of X-linked genes.
Supporting Evidence
- The study used data from a large-scale expression study in human monocytes.
- Filtering methods significantly affected the estimated X∶AA ratio.
- Using a uniform filtering threshold led to an over-estimation of X-linked expressions.
- The hypothesis of dosage compensation was rejected when using chromosome-specific filtering.
- Results were consistent across different tissues analyzed.
Takeaway
This study shows that how we filter gene data can change our understanding of how genes on the X chromosome are expressed compared to other genes.
Methodology
Microarray expression data from circulating monocytes in 1,467 individuals were analyzed using two different filtering methods to compare X-linked and autosomal gene expressions.
Potential Biases
Potential bias arises from using a uniform detection threshold that may disproportionately exclude lowly expressed genes on the X chromosome.
Limitations
The study's conclusions are dependent on the biological assumptions regarding the proportion of actively expressed genes on the X chromosome compared to autosomes.
Participant Demographics
1,467 unrelated subjects (51.1% men) of European descent aged 35–74 years.
Statistical Information
P-Value
p<10−31
Confidence Interval
95% bootstrap confidence intervals
Statistical Significance
p<10−31
Digital Object Identifier (DOI)
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