title: "Breaking news" from spermatids.
abstract: During the haploid phase of spermatogenesis, spermatids undergo a complex remodeling of the paternal genome involving the finely orchestrated replacement of histones by the highly-basic protamines. The associated striking change in DNA topology is characterized by a transient surge of both single- and double-stranded DNA breaks in the whole population of spermatids which are repaired before spermiation. These transient DNA breaks are now considered part of the normal differentiation program of these cells. Despite an increasing interest in the study of spermiogenesis in the last decade and the potential threat to the haploid genome, the origin of these DNA breaks still remains elusive. This review briefly outlines the current hypotheses regarding possible mechanisms that may lead to such transient DNA fragmentation including torsional stress, enzyme-induced breaks, apoptosis-like processes or oxidative stress. A better understanding of the origin of these DNA breaks will lead to further investigations on the genetic instability and mutagenic potential induced by the chromatin remodeling.
authors.affiliation: Dept of Biochemistry, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Pavillon Z8, 3201 Jean-Mignault St, Sherbrooke, Quebec J1E 4K8 Canada.
authors.forename: Anne
authors.initials: A
authors.lastname: Gouraud
authors.affiliation: Dept of Biochemistry, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Pavillon Z8, 3201 Jean-Mignault St, Sherbrooke, Quebec J1E 4K8 Canada.
authors.forename: Marc-André
authors.initials: MA
authors.lastname: Brazeau
authors.affiliation: Dept of Biochemistry, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Pavillon Z8, 3201 Jean-Mignault St, Sherbrooke, Quebec J1E 4K8 Canada.
authors.forename: Marie-Chantal
authors.initials: MC
authors.lastname: Grégoire
authors.affiliation: Dept of Biochemistry, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Pavillon Z8, 3201 Jean-Mignault St, Sherbrooke, Quebec J1E 4K8 Canada.
authors.forename: Olivier
authors.initials: O
authors.lastname: Simard
authors.affiliation: Dept of Biochemistry, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Pavillon Z8, 3201 Jean-Mignault St, Sherbrooke, Quebec J1E 4K8 Canada.
authors.forename: Julien
authors.initials: J
authors.lastname: Massonneau
authors.affiliation: Dept of Biochemistry, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Pavillon Z8, 3201 Jean-Mignault St, Sherbrooke, Quebec J1E 4K8 Canada.
authors.forename: Mélina
authors.initials: M
authors.lastname: Arguin
authors.affiliation: Dept of Biochemistry, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Pavillon Z8, 3201 Jean-Mignault St, Sherbrooke, Quebec J1E 4K8 Canada.
authors.forename: Guylain
authors.initials: G
authors.lastname: Boissonneault
keywords: Apoptosis; Chromatin remodeling; DNA break; Oxidative stress; Spermiogenesis; Topoisomerase; Torsional stress