Can oocytes repair fragmented DNA of spermatozoa?

Abstract Approximately half of the cases of infertility are due to male factor. In many cases the underlying cause of male infertility is not discovered and, therefore, the condition is considered idiopathic. Examination of morphology, motility, concentration and total sperm count is very important but not sufficient for complex men fertility evaluation. Sperm DNA integrity is a very important one. Sperm DNA can be fragmented by several internal or external factors. In immature sperm cells, the DNA can be repaired by reparatory mechanisms of spermatogonia or spermatocytes. However, in a haploid mature sperm cell, these fragments can not be repaired by male and the fragmented DNA is transferred to oocyte. Oocytes are able to repair male fragmented DNA after their fertilization. A quality embryo can repair damaged sperm DNA and the repair system depends on cytoplasmic and genomic quality of the oocyte. The ability of oocyte to repair sperm DNA strong depend on quality of fertilized oocytes. Running title: Oocyte and DNA repair