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 spe
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Contact: Richard Lane
richard.lane@lancet.com
44-207-424-4949
Lancet
5-Sep-2002