Deletions on mouse Yq lead to upregulation of multiple X- and Y-linked transcripts in spermatids.
Deletions on the mouse Y-chromosome long arm (MSYq) lead to teratozoospermia and in severe cases to infertility. We find that the downstream transcriptional changes in the testis resulting from the loss of MSYq-encoded transcripts involve upregulation of multiple X- and Y-linked spermatid-expressed genes, but not related autosomal genes. Therefore, this indicates that in normal males, there is a specific repression of X and Y (gonosomal) transcription in post-meiotic cells, which depends on MSYq-encoded transcripts. Together with the known sex ratio skew in favour of females in the offspring of fertile MSYqdel males, this strongly suggests the existence of an intragenomic conflict between X- and Y-linked genes. Two potential antagonists in this conflict are the X-linked multicopy gene Xmr and its multicopy MSYq-linked relative Sly, which are upregulated and downregulated, respectively, in the testes of MSYqdel males. Xmr is also expressed during meiotic sex chromosome inactivation (MSCI), indicating a link between the MSCI and the MSYq-dependent gonosomal repression in spermatids. We therefore propose that this repression and MSCI itself are evolutionary adaptations to maintain a normal sex ratio in the face of X/Y antagonism.
Ellis
Peter J I
PJ
Department of Pathology, Mammalian Molecular Genetics Group, University of Cambridge, Tennis Court Road, Cambridge CB2 1QP, UK.
Clemente
Emily J
EJ
Ball
Penny
P
Touré
Aminata
A
Ferguson
Lydia
L
Turner
James M A
JM
Loveland
Kate L
KL
Affara
Nabeel A
NA
Burgoyne
Paul S
PS
D048868:Adaptor Proteins, Signal Transducing / Q000378:metabolism; D033942:Adaptor Proteins, Vesicular Transport; D000818:Animals; D015152:Blotting, Northern; D015139:Blotting, Southern; D017353:Gene Deletion; D005786:Gene Expression Regulation; D050172:Genes, X-Linked / Q000235:genetics*; D050173:Genes, Y-Linked / Q000235:genetics*; D017403:In Situ Hybridization; D008297:Male; D051379:Mice; D046228:Microarray Analysis; D005810:Multigene Family / Q000235:genetics; D009687:Nuclear Proteins / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012744:Sex Ratio; D013087:Spermatids / Q000378:metabolism*; D049951:X Chromosome Inactivation / Q000235:genetics; D014998:Y Chromosome / Q000235:genetics*
D048868:Adaptor Proteins, Signal Transducing; D033942:Adaptor Proteins, Vesicular Transport; D009687:Nuclear Proteins; C506091:SLY1 protein, mouse; C085792:Slx protein, mouse