No partial DAZ deletions but frequent gene conversion events on the Y chromosome of fertile men.
OBJECTIVE
Recently, partial DAZ deletions on the Y chromosome were identified in infertile men. To determine the clinical importance of partial DAZ deletion, we studied the number of DAZ copies in a well-defined population of 47 fertile men.


METHODS
The number of DAZ gene copies was determined by PCR assays, qualitative and quantitative DNA blot experiments.


RESULTS
Using semi-quantitative Southern blot, no partial DAZ deletion was detected in fertile men. In many cases, the results were discordant with the PCR assays and qualitative DYS1-blot experiments suggesting that the molecular events detected by the later methods could reflect gene conversion events. Many fertile men present four copies of the DAZ genes but an atypical organization of this DAZ locus. No difference in sperm concentration and motility in the fertile men were observed according to the different DAZ-haplotypes.


CONCLUSIONS
The different DAZ-haplotypes are compatible with normal spermatogenesis.
Lepretre
Anne Claire
AC
Laboratoire de Biochimie et Génétique Moléculaires, CHU Cochin, 123 bld de Port-Royal, 75014 Paris, France.
Patrat
Catherine
C
Mitchell
Michael
M
Jouannet
Pierre
P
Bienvenu
Thierry
T
D000328:Adult; D015139:Blotting, Southern; D041322:Chromosomes, Human, Y / Q000235:genetics*; D004252:DNA Mutational Analysis; D000075364:Deleted in Azoospermia 1 Protein; D005298:Fertility / Q000235:genetics*; D005785:Gene Conversion; D006239:Haplotypes; D006801:Humans; D008297:Male; D016133:Polymerase Chain Reaction; D016601:RNA-Binding Proteins / Q000235:genetics*; D013091:Spermatogenesis / Q000502:physiology
C095668:DAZ1 protein, human; D000075364:Deleted in Azoospermia 1 Protein; D016601:RNA-Binding Proteins