MOLECULAR ANALYSIS OF A HUMAN-Y 1-TRANSLOCATION IN AN AZOOSPERMIC MALE

Cytogenetic studies on an azoospermic male revealed a balanced Y;1 tra nslocation: 46,X,t(Y;1)(q12;p34.3). In situ hybridization with the pro be St35-239 (DXY64) and with a probe detecting telomeric sequences rev ealed that only the Y telomere is involved in the translocation. Fluor escence in situ hybridization with a chromosome 1 library on meiotic p reparations revealed consistent contact of the painted chromosome 1 wi th the sex vesicle at pachytene, the most advanced stage of spermatoge nesis observed. No deletions were observed after Southern blot analysi s with probes p49f (DYS 1), 50f2 (DYS7), and 52d (DYF27), which map in interval 6 of the Y chromosome, which includes the azoospermia factor (AZF) gene. The results indicate that the infertility of the transloc ation carrier could be due to an alteration of the sex vesicle structu re or to a disturbance of X-chromosome inactivation as a result of the proximity to the autosomal portion.