TY - JOUR
T1 - Recombination in the pseudoautosomal region in a 47, XYY male
AU - Aw, Bee Yan
AU - Chung, Sukkyun
AU - Roberts, Mark J.
N1 - Funding Information:
Acknowledgements The authors are grateful to the sperm donor who made this study possible. This research was supported by the Canadian Institutes for Health Research (grant to R.H.M.).
PY - 2001
Y1 - 2001
N2 - Males with a 47, XYY karyotype generally have chromosomally normal children, despite the high theoretical risk of aneuploidy. Studies of sperm karyotypes or FISH analysis of sperm have demonstrated that the majority of sperm are chromosomally normal in 47, XYY men. There have been a number of meiotic studies of XYY males attempting to determine whether the additional Y chromosome is eliminated during spermatogenesis, with conflicting results regarding the pairing of the sex chromosomes and the presence of an additional Y. We analyzed recombination in the pseudoautosomal region of the XY bivalent to determine whether this is perturbed in a 47, XYY male. A recombination frequency similar to normal 46, XY men would indicate normal pairing within the XY bivalent, whereas a significantly altered frequency would suggest other types of pairing such as a YY bivalent or an XYY trivalent. Two DNA markers, STS/STS pseudogene and DXYS15, were typed in sperm from a heterozygous 47, XYY male. Individual sperm (23, X or Y) were isolated into PCR tubes using a FACStarPlus flow cytometer. Hemi-nested PCR analysis of the two DNA markers was performed to determine the frequency of recombination. A total of 108 sperm was typed with a 38% recombination frequency between the two DNA markers. This is very similar to the frequency of 38.3% that we have observed in 329 sperm from a normal 46, XY male. Thus our results suggest that XY pairing and recombination occur normally in this 47, XYY male. This could occur by the production of an XY bivalent and Y univalent (which is then lost in most cells) or by loss of the additional Y chromosome in some primitive germ cells or spermatogonia and a proliferative advantage of the normal XY cells.
AB - Males with a 47, XYY karyotype generally have chromosomally normal children, despite the high theoretical risk of aneuploidy. Studies of sperm karyotypes or FISH analysis of sperm have demonstrated that the majority of sperm are chromosomally normal in 47, XYY men. There have been a number of meiotic studies of XYY males attempting to determine whether the additional Y chromosome is eliminated during spermatogenesis, with conflicting results regarding the pairing of the sex chromosomes and the presence of an additional Y. We analyzed recombination in the pseudoautosomal region of the XY bivalent to determine whether this is perturbed in a 47, XYY male. A recombination frequency similar to normal 46, XY men would indicate normal pairing within the XY bivalent, whereas a significantly altered frequency would suggest other types of pairing such as a YY bivalent or an XYY trivalent. Two DNA markers, STS/STS pseudogene and DXYS15, were typed in sperm from a heterozygous 47, XYY male. Individual sperm (23, X or Y) were isolated into PCR tubes using a FACStarPlus flow cytometer. Hemi-nested PCR analysis of the two DNA markers was performed to determine the frequency of recombination. A total of 108 sperm was typed with a 38% recombination frequency between the two DNA markers. This is very similar to the frequency of 38.3% that we have observed in 329 sperm from a normal 46, XY male. Thus our results suggest that XY pairing and recombination occur normally in this 47, XYY male. This could occur by the production of an XY bivalent and Y univalent (which is then lost in most cells) or by loss of the additional Y chromosome in some primitive germ cells or spermatogonia and a proliferative advantage of the normal XY cells.
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U2 - 10.1007/s004390100566
DO - 10.1007/s004390100566
M3 - Article
C2 - 11511918
AN - SCOPUS:0034845696
SN - 0340-6717
VL - 109
SP - 143
EP - 145
JO - Human genetics
JF - Human genetics
IS - 2
ER -