title: DNA fragmentation of spermatozoa and assisted reproduction technology.
abstract: Despite the ever-increasing knowledge of the fertilization process, there is still a need for better understanding of the causes of sperm DNA fragmentation and its impact on fertilization and pregnancy. For this reason, human sperm DNA fragmentation was investigated by means of the terminal deoxynucleotidyl transferase-mediated dUDP nick-end labelling (TUNEL) assay and the production of reactive oxygen species (ROS) in the ejaculate and in the spermatozoa themselves. These data were correlated with fertilization and pregnancy data from IVF and intracytoplasmic sperm injection (ICSI) patients. Sperm DNA fragmentation did not correlate with fertilization rate, but there was a significantly reduced pregnancy rate in IVF patients inseminated with TUNEL-positive spermatozoa. ICSI patients exhibited the same tendency. This implies that spermatozoa with damaged DNA are able to fertilize an oocyte, but at the time the paternal genome is switched on, further development stops. The determination of ROS in the ejaculate and the percentage of ROS-producing spermatozoa revealed markedly stronger correlations between sperm functions (i.e. motility) and the percentage of ROS-producing spermatozoa. The influence of seminal leukocytes, known to produce large amounts of oxidants, on sperm DNA fragmentation should not be neglected.
authors.affiliation: Centre for Dermatology and Andrology, Justus Liebig University, Gaffkystrasse 14, D-35385 Giessen, Germany. ralf.henkel@derma.med.uni-giessen.de
authors.forename: Ralf
authors.initials: R
authors.lastname: Henkel
authors.forename: Eva
authors.initials: E
authors.lastname: Kierspel
authors.forename: Marjam
authors.initials: M
authors.lastname: Hajimohammad
authors.forename: Thomas
authors.initials: T
authors.lastname: Stalf
authors.forename: Christiaan
authors.initials: C
authors.lastname: Hoogendijk
authors.forename: Claas
authors.initials: C
authors.lastname: Mehnert
authors.forename: Roelof
authors.initials: R
authors.lastname: Menkveld
authors.forename: Wolf-Bernhard
authors.initials: WB
authors.lastname: Schill
authors.forename: Thinus F
authors.initials: TF
authors.lastname: Kruger
mesh_terms: D004249:DNA Damage; D053938:DNA Fragmentation; D005260:Female; D005307:Fertilization in Vitro / Q000379:methods; D006801:Humans; D020287:In Situ Nick-End Labeling; D007248:Infertility, Male; D007962:Leukocytes / Q000378:metabolism; D008297:Male; D016877:Oxidants / Q000378:metabolism; D011247:Pregnancy; D017382:Reactive Oxygen Species; D012099:Reproductive Techniques; D020554:Sperm Injections, Intracytoplasmic / Q000379:methods; D013094:Spermatozoa / Q000378:metabolism* / Q000473:pathology / Q000648:ultrastructure
chemical_list: D016877:Oxidants; D017382:Reactive Oxygen Species