Perturbation of genomic imprinting in oligozoospermia.

The role of epigenetic modifications in oligozoospermia and other disorders of spermatogenesis remains poorly understood. While a variety of environmental, nutritional and genetic abnormalities can cause oligozoospermia, a condition associated with infertility, it is unclear whether chromatin modifications might be also involved in impaired spermatogenesis. Several recent studies addressed this question and reported abnormal DNA methylation patterns in sperm from oligozoospermic men. Altered DNA methylation was detected specifically at sequence elements that control imprinted gene expression. This remarkable finding suggests that defects in spermatogenesis could be linked to the epigenetic regulation of imprinting in the male germ line. In addition, they raise concerns as to whether aberrant imprints in the male germ cells can have health implications for the next generation.