No severe and global X chromosome inactivation in meiotic male germline of Drosophila
Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD, USA
BMC Biology 2012, 10:50 doi:10.1186/1741-7007-10-50Published: 12 June 2012
This article is a response to Vibranovski et al.
We have previously reported a high propensity of testis-expressed X-linked genes to activation in meiotic cells, a similarity in global gene expression between the X chromosome and autosomes in meiotic germline, and under-representation of various types of tissue-specific genes on the X chromosome. Based on our findings and a critical review of the current literature, we believe that there is no global and severe silencing of the X chromosome in the meiotic male germline of Drosophila. The term 'meiotic sex chromosome inactivation' (MSCI) therefore seems misleading when used to describe the minor underexpression of the X chromosome in the testis of Drosophila, because this term erroneously implies a profound and widespread silencing of the X-linked genes, by analogy to the well-studied MSCI system in mammals, and therefore distracts from identification and analysis of the real mechanisms that orchestrate gene expression and evolution in this species.