Journal of Molecular Evolution

, Volume 68, Issue 5, pp 576–583

The Deficit of Male-Biased Genes on the D. melanogaster X Chromosome Is Expression-Dependent: A Consequence of Dosage Compensation?


DOI: 10.1007/s00239-009-9235-4

Cite this article as:
Vicoso, B. & Charlesworth, B. J Mol Evol (2009) 68: 576. doi:10.1007/s00239-009-9235-4


In Drosophila, there is a consistent deficit of male-biased genes on the X chromosome. It has been suggested that male-biased genes may evolve from initially unbiased genes as a result of increased expression levels in males. If transcription rates are limited, a large increase in expression in the testis may be harder to achieve for single-copy X-linked genes than for autosomal genes, because they are already hypertranscribed due to dosage compensation. This hypothesis predicts that the larger the increase in expression required to make a male-biased gene, the lower the chance of this being achievable if it is located on the X chromosome. Consequently, highly expressed male-biased genes should be located on the X chromosome less often than lowly expressed male-biased genes. This pattern is observed in our analysis of publicly available data, where microarray data or EST data are used to detect male-biased genes in D. melanogaster and to measure their expression levels. This is consistent with the idea that limitations in transcription rates may prevent male-biased genes from accumulating on the X chromosome.


Drosophila melanogaster Sex-biased genes Genomic distribution X chromosome Dosage compensation 

Supplementary material

239_2009_9235_MOESM1_ESM.doc (86 kb)
Supplementary material 1 (DOC 86 kb)

Copyright information

© Springer Science+Business Media, LLC 2009

Authors and Affiliations

  1. 1.Institute of Evolutionary Biology, School of Biological SciencesUniversity of Edinburgh, Ashworth LaboratoriesEdinburghUK

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