Low chiasma frequency as an aetiological factor in male infertility.
Among 120 meiotic analyses of infertile men there were three cases with a particular meiotic anomaly: low chiasma count at diakinesis and spermatogenic arrest. All clinical findings, hormonal analyses and karyotypes from peripheral blood were normal. Meiotic studies showed that pachytene pairing was complete, but in diakinesis the mean number of chiasmata per cell was significantly lowered, chromosomes were fragmented and univalents could frequently be found. In all three cases azoospermia was the consequence of spermatogenic arrest, which occurred after diakinesis-metaphase I.
D000328:Adult; D002875:Chromosomes / Q000648:ultrastructure*; D006801:Humans; D008297:Male; D008540:Meiosis; D009845:Oligospermia / Q000235:genetics* / Q000473:pathology; D013091:Spermatogenesis; D013093:Spermatogonia / Q000648:ultrastructure