Fertility in mice requires X-Y pairing and a Y-chromosomal "spermiogenesis" gene mapping to the long arm.
There is accumulating evidence that the mammalian Y chromosome, in addition to its testis-determining function, may have other male limited functions, particularly in spermatogenesis. We have previously shown that the short arm of the mouse Y carries information needed for spermatogonial proliferation. This information, together with the testis-determining gene Sry, is contained within the Y-derived sex reversal factor Sxra. XO males carrying a copy of Sxra attached to the X chromosome are nevertheless sterile owing to an almost complete arrest during the meiotic metaphase stages. Here we show that this meiotic block can be overcome by providing a meiotic pairing partner (with no Y-specific DNA) for the XSxra chromosome. However, this does not restore fertility because the sperm produced all have abnormal heads. It is concluded that the Y-specific region of the mouse Y chromosome long arm includes information essential for the normal development of the sperm head.
Burgoyne
P S
PS
MRC Mammalian Development Unit, Wolfson House, London, England.
Mahadevaiah
S K
SK
Sutcliffe
M J
MJ
Palmer
S J
SJ
D000818:Animals; D002874:Chromosome Mapping; D005298:Fertility / Q000235:genetics*; D008297:Male; D008540:Meiosis / Q000235:genetics*; D051379:Mice; D013077:Sperm Head / Q000648:ultrastructure; D013091:Spermatogenesis / Q000235:genetics*; D014960:X Chromosome / Q000502:physiology; D014998:Y Chromosome / Q000502:physiology*