SSTY proteins co-localize with the post-meiotic sex chromatin and interact with regulators of its expression.
In mammals, X- and Y-encoded genes are transcriptionally shut down during male meiosis, but expression of many of them is (re)activated in spermatids after meiosis. Post-meiotic XY gene expression is regulated by active epigenetic marks, which are de novo incorporated in the sex chromatin of spermatids, and by repressive epigenetic marks inherited during meiosis; alterations in this process lead to male infertility. In the mouse, post-meiotic XY gene expression is known to depend on genetic information carried by the male-specific region of the Y chromosome long arm (MSYq). The MSYq gene Sly has been shown to be a key regulator of post-meiotic sex chromosome gene expression and is necessary for the maintenance/recruitment of repressive epigenetic marks on the sex chromatin, but studies suggest that another MSYq gene may also be required. The best candidate to date is Ssty, an MSYq multi-copy gene of unknown function. Here, we show that SSTY proteins are specifically expressed in round and elongating spermatids, and co-localize with post-meiotic sex chromatin. Moreover, SSTY proteins interact with SLY protein and its X-linked homolog SLX/SLXL1, and may be required for localization of SLX/SLY proteins in the spermatid nucleus and sex chromatin. Our data suggest that SSTY is a second MSYq factor involved in the control of XY gene expression during sperm differentiation. As Slx/Slxl1 and Sly genes have been shown to be involved in the XY intra-genomic conflict, which affects the offspring sex ratio, Ssty may constitute another player in this conflict.
Institut National de la Santé et de la Recherche Médicale (INSERM) U1016, Institut Cochin, Paris, France; Centre National de la Recherche Scientifique, UMR8104, Paris, France; Faculté de Médecine, Université Paris Descartes, Paris, France.
Aurélie
A
Comptour
Charlotte
C
Moretti
Maria-Elisabetta
ME
Serrentino
Jana
J
Auer
Côme
C
Ialy-Radio
Monika A
MA
Ward
Aminata
A
Touré
Daniel
D
Vaiman
Julie
J
Cocquet
D000595:Amino Acid Sequence; D000818:Animals; D002467:Cell Nucleus / Q000378:metabolism; D044127:Epigenesis, Genetic; D005260:Female; D005786:Gene Expression Regulation; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000172:deficiency / Q000235:genetics / Q000378:metabolism; D011506:Proteins / Q000235:genetics* / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D012728:Sex Chromatin / Q000235:genetics* / Q000378:metabolism*; D013087:Spermatids / Q000378:metabolism; D013091:Spermatogenesis / Q000235:genetics; D014960:X Chromosome / Q000235:genetics; D014998:Y Chromosome / Q000235:genetics
D009687:Nuclear Proteins; D011506:Proteins; C085792:Slx protein, mouse; C562172:Slx-like1 protein, mouse; C491842:Ssty1 protein, mouse
chromatin; germ cells; intra-genomic conflict; sex chromosomes; spermatogenesis