Use of deoxyribonucleic acid probes to test for Yq11 deletions in males with spermatogenic arrest.

A cytogenetically detectable deletion in the area of Yq11 has been demonstrated in some men with spermatogenic arrest, leading to the suggestion that a spermatogenic factor(s) lies within this region. The probe pAS1 detects an argininosuccinate synthetase pseudogene 6 (ASSP6), which has been mapped to Ycen-q11. The 4B-2 (DYS 15) probe detects a single-copy 3.3 kb EcoRI fragment that maps to the proximal portion of the Y long arm located distal to the sequence detected by the pAS1 probe. Deoxyribonucleic acid (DNA) samples from normal males and females and ten males with spermatogenic arrest were digested with the restriction endonuclease EcoRI, electrophoresed on agarose gels, Southern blotted, and hybridized with the pAS1 and 4B-2 probes. All males tested, including the ten azoospermic males with spermatogenic arrest, exhibited 4.3 kb and 3.3 kb male specific fragments with the pAS1 and 4B-2 probes, respectively. From preliminary analyses, the authors conclude that the regions detected by these two probes are not absent in these azoospermic males and that the cause of their spermatogenic arrest may not involve deletion within this region. Molecular defects affecting spermatogenesis may involve loss of sequences at Yq11, which were not tested in the study, or they may derive from heterogenous causes.