Quantitative analysis of gene-specific DNA damage in human spermatozoa Sawyer, Dennis E; Mercer, Belinda G; Wiklendt, Agnieszka M; Aitken, R John 60 APPLIED LIFE SCIENCES; BIOLOGICAL STRESS; DNA; ELECTROPHORESIS; GELS; GENES; GLOBINS; HYDROGEN PEROXIDE; IN VITRO; IRON; POLYMERASE CHAIN REACTION; SPERMATOZOA; STRAND BREAKS; SULFATES Recent studies have suggested that human spermatozoa are highly susceptible to DNA damage induced by oxidative stress. However, a detailed analysis of the precise nature of this damage and the extent to which it affects the mitochondrial and nuclear genomes has not been reported. To induce DNA damage, human spermatozoa were treated in vitro with hydrogen peroxide (H{sub 2}O{sub 2}; 0-5 mM) or iron (as Fe(II)SO{sub 4}, 0-500 {mu}M). Quantitative PCR (QPCR) was used to measure DNA damage in individual nuclear genes (hprt, {beta}-pol and {beta}-globin) and mitochondrial DNA. Single strand breaks were also assessed by alkaline gel electrophoresis. H{sub 2}O{sub 2} was found to be genotoxic toward spermatozoa at concentrations as high as 1.25 mM, but DNA damage was not detected in these cells with lower concentrations of H{sub 2}O{sub 2}. The mitochondrial genome of human spermatozoa was significantly (P<0.001) more susceptible to H{sub 2}O{sub 2}-induced DNA damage than the nuclear genome. However, both nDNA and mtDNA in human spermatozoa were significantly (P<0.001) more resistant to damage than DNA from a variety of cell lines of germ cell and myoblastoid origin. Interestingly, significant DNA damage was also not detected in human spermatozoa treated with iron. These studies report, for the first time, quantitative measurements of DNA damage in specific genes of male germ cells, and challenge the commonly held belief that human spermatozoa are particularly vulnerable to DNA damage. Netherlands 2003-08-28 English Journal Article Journal Name: Mutation Research; Journal Volume: 529; Journal Issue: 1-2; Other Information: DOI: 10.1016/S0027-5107(03)00101-5; PII: S0027510703001015; Copyright (c) 2003 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA) Medium: X; Size: page(s) 21-34 https://doi.org/10.1016/S0027-5107(03)00101-5 [] 1-2 529 Journal ID: ISSN 0027-5107; MUREAV; TRN: NL05S9011094071 NLN 2010-12-31 20654471