Nuevos enfoques en el estudio y diagnóstico de la infertilidad masculina. Aportaciones de la investigación básica al conocimiento de la función espermática

Higher incidence of infertility problems has been observed in recent years, specially in developed countries. The infertility causes may be diverse, but it is estimated that approximately half of the cases are related to male factor. However, basic and applied research on male infertility did not generate much interest. One of the key stages in the fertility process is related to the sperm zona pellucida (ZP) recognition, ZP acts as a barrier between the male and female gamete. The interaction between sperm and ZP is mediated by specific receptors. They are capable or inducing acrosome reaction or acrosomal exocytosis on sperm cells, and to start the ZP penetration process which culminates with oocyte fusion. Therefore, defects on sperm recognizing this structure may inhibited zygote formation. To study this stage of the fertilization process may help the clinician choosing the most accurate treatment for the infertile couple. Nevertheless, difficulties to obtain native ZP have limited the advances in this specific area of research in reproductive medicine. In this review, we summarize, up to date, the efforts realized towards the diagnosis of the alfunctions in the recognition between human sperm and the ZP, including the new approaches focus on studying and understanding this key stage on the fertilization process.