STUDIES ON MEIOTIC CHROMOSOMES IN INFERTILE MEN AND CONTROLS WITH NORMAL KARYOTYPES

Abstract

Summary. The meiotic chromosomes in diakinesis—metaphase I (MI) and metaphase II (MII) of eighteen controls and seventy-four infertile men with a normal 46,XY chromosome complement were investigated. The MII/MI ratio was decreased in the infertile group. The difference in mean chiasma frequency between the two groups was not statistically significant, but there was a significant variation between individuals. In three infertile men, a small proportion of cells in MI contained indistinct, grossly fragmented chromosomes with low chiasma frequency. The non-pairing of sex chromosomes and homologous autosomes in MI was the same in the controls and infertile men. One hundred and seventy-four cells (15%) of 1159 cells contained non-paired sex chromosomes and in six cells (0·5%), two small homologous chromosomes were separated. Non-pairing may give rise to zygotes with abnormal chromosome complements. The relative number of polyploid cells in MII, but not in spermatogonial metaphase and MI, was significantly increased in the infertile men. No structural abnormalities were detected.