News Release

Study identifies genetic fingerprint of healthy sperm

N.B. Please note that if you are outside North America the embargo date for all Lancet Press material is 0001 hours UK time Friday 6 September 2002

Peer-Reviewed Publication

The Lancet_DELETED

The genetic fingerprinting of sperm cells--detailed in this week's issue of THE LANCET--could be a major step forward in our understanding of male infertility.

Around one in six couples experience difficulty in conceiving a child, and male fertility problems account for half of assisted reproductive techniques. However, the underlying cause of infertility is essentially unknown in about two-thirds of infertile men who undergo infertility assessment.

Findings from several studies suggest that sperm cells have a complex genetic code made up of components called messenger RNA (mRNA). Stephen Krawetz from Wayne State University, Detroit, USA, David Miller from the University of Leeds, UK, and David Dix from the Environmental Protection Agency, North Carolina, USA, investigated whether mRNAs from sperm cells could be used to generate a genetic fingerprint of the sperm of fertile men. The investigators used genetic mapping techniques to assess sperm mRNAs from 19 testes, a pool of sperm cells from nine individual ejaculates, and from sperm cells from a single ejaculate.

Analysis of sperm cells in the study identified around 3000 individual mRNAs for the fertile male. The investigators comment that this non-invasive 'gold standard' can be used in the future as a benchmark for comparisons of genetic analysis from sperm of infertile men; future analysis should identify the defective genes that contribute to infertility. Furthermore, the investigators suggest that some of the mRNA in healthy sperm could contribute to the viability of the zygote after fertilisation.

Stephen Krawetz comments: "We have completed a genome-wide analysis to define the spermatozoal RNA fingerprint of normal fertile men. By contrast with assessments of semen quality that rely on subjective physiological and morphological criteria, the methods outlined in this study provide a unique and objective opportunity to identify and diagnose idiopathic infertilities with spermatozoal mRNA fingerprints. The spermatozoal fingerprint of normal fertile men could help to elucidate the underlying causes of male-factor infertility and begin to reveal why mRNAs remain in mature spermatozoa."

In an accompanying Commentary (p 742), Gerald Schatten from the University of Pittsburgh School of Medicine, USA, states: "Less than 3000 different mRNAs define fertile sperm…these mRNAs may become invaluable for: new diagnostics for idiopathic infertility; discovering paternal influences to both the fetus and the placenta; ascertaining if there are generational consequences of environmental exposures of boys and men; new strategies for male contraception…Are sperm mRNAs remnants of their past lives during spermatogenesis, especially spermiogenesis, or vital packets essential to energise embryos? Such information is especially important for its prognostic value when evaluating each sperm's reproductive potential."

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Additional Contact Information:
Dr. Stephen A Krawetz,
Wayne State University School of Medicine,
253 CS Mott Center,
275 East Hancock,
Detroit, MI 48201, USA;
T) 313-577-6770;
F) 313-577-8554;
E) steve@compbio.med.wayne.edu

Dr David Miller, c/o Abigail Chard,
Press Office, University of Leeds,
Leeds, LS2 9JT, UK;
T)+44-113-343-6699;
F) 44-113-343-4125;
E) a.chard@adm.leeds.ac.uk

David Dix, Research Biologist,
Reproductive Toxicology Division (MD-72)
National Health and Environmental Effects Research Laboratory,
US Environmental Protection Agency,
Research Triangle Park, NC 27711, UA;
T) 919-541-2701;
F) 919-541-4017;
E) dix.david@epa.gov

Professor Gerald P Schatten,
Department of Obstetrics, Gynecology, Reproductive Sciences,Cell Biology and Physiology,
University of Pittsburgh School of Medicine,
Magee-Womens Research Institute,
204 Craft Avenue,
Pittsburgh, PA 15213, USA;
T) 412-641-2400;
F) 412-641-2410;
E) pdcgs@mail.magee.edu


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