Meiotic behaviour and sperm aneuploidy in an infertile man with a mosaic 45, X/46, XY karyotype

作者：Ren, He; Chow, Victor; Ma, Sai^*

来源：Reproductive BioMedicine Online, 2015, 31(6): 783-789.

DOI：10.1016/j.rbmo.2015.08.016

• male infertility
• meiosis
• meiotic sex chromosome inactivation
• sex chromosome mosaicism
• univalent X chromosome
• unpaired sex chromosomes

The meiotic behaviour of the germ cells in 45, X/46, XY men has not been extensively studied. This study investigated the meiotic events and sperm aneuploidy in an azoospermic man with a 45, X/46, XY (50/50) mosaic karyotype to better understand the fate of the 45, X cells and the production of chromosomally abnormal spermatozoa. Combining immunofluorescence techniques and fluorescence in-situ hybridization, meiotic recombination, synapsis, meiotic sex chromosome inactivation (MSCI) and configuration were analysed, as well as sperm aneuploidy in the patient and 10 normal, fertile men. Despite the 50: 50 somatic mosaicism in the patient, 25% of pachytene cells analysed were 45, X. Furthermore, 63% of pachytene cells were 46, XY with paired sex chromosomes, and 12% were 46, XY with unpaired sex chromosomes, which displayed abnormal MCSI patterns. Although the patient's testicular spermatozoa showed increased aneuploidy, the majority were of normal constitution. The X:Y sperm ratio was significantly increased compared with the controls (P < 0.001), which may indicate that some 45, X cells gave rise to X-bearing spermatozoa. The findings provide insight into the fate of 45, X/46, XY cells in meiosis, supporting the hypothesis that stringent checkpoints ensure the favourable production of spermatozoa with normal chromosomal constitution despite an individual's abnormal karyotype.

• 出版日期2015-12