Journal of Fertilization: In Vitro - IVF-Worldwide, Reproductive Medicine, Genetics & Stem Cell Biol
Open Access

Abstract

Is sperm chromatin packaging relevant for IVF success?

Elisabetta Tosti and Adriana Fortunato

Spermiogenesis is the last phase of the process that give rise to a mature and competent spermatozoon. It occurs from a dramatic morphological and structural change of the spermatid, in particular replacement of DNA-linked histones by protamines leading to a highly compact chromatin structure consisting of DNA and heterogeneous nucleoproteins. The target of a fertilizing spermatozoon is to deliver into the oocyte the paternal genome and regulatory factors that are required for proper embryonic development [1]. To do this the sperm must be capable of undergoing decondensation at a peculiar moment of the fertilization process. Increasing evidence on the strong paternal effect on preimplantation embryo development [2] focus on the importance to identify a reliable sperm quality parameter. Although many different causes may give rise to male infertility [3], traditionally in IVF centres, routine laboratory investigations evaluate seminal parameters such as concentration, motility and morphology in order to assess semen quality prior to undergo assisted reproduction. Recent acquisitions correlate poor chromatin condensation to a failure in fertilization, embryo development and repeated miscarriages indicating even that sperm DNA damage over 30% impedes natural pregnancy.