A human 9;20 reciprocal translocation associated with male infertility analyzed at prophase and metaphase I of meiosis.

Details are given of a meiotic prophase analysis, carried out by spreading, of a human 9;20 reciprocal translocation ascertained in a subfertile, oligospermic male. Air-dried meiotic preparations revealed the presence of translocation quadrivalents at metaphase I. Germ-cell degeneration was evident from the early prophase of meiosis onward. Associations between the translocation quadrivalent and XY bivalent at pachytene were seen in only 20% of the cells and seemed not to be the prime cause of germ-cell failure. Pairing disruption around the breakpoints of the translocation at pachytene and/or pairing failure in one arm of the pachytene cross was observed in a total of 87% of all cells analyzed. This could have contributed significantly to germ-cell atresia.