A novel prognostic factor for infertility
At ovulation, mammalian oocytes are arrested at metaphase-II and may only be released from this state when fertilised by a spermatozoon. Over the past few years, accumulating evidence has supported the crucial role of the sperm-specific protein phospholipase C ζ (PLCζ) on the activation of the oocyte. Although many cases of male infertility can be rescued by intra-cytoplasmic sperm injection, this approach fails to treat PLCζ deficiency. Recombinant PLCζ is emerging as a safe therapeutic option for male infertility but there is no information on how it interacts with oocyte-based factors to regulate functionality. Scientists on the EU-funded OOCYTE ACTIVATION (Oocyte activation and human infertility: Identification and characterisation of a critical oocyte-borne receptor and effects of laboratory procedures upon key proteins involved in oocyte activation) project set out to study the presence and localisation patterns of PLCζ in human sperm. For this purpose, they analysed samples from fertile and non-fertile men. They observed that following intracytoplasmic injection, the presence and localisation patterns of PLCζ in human sperm correlated to fertilisation rates. This suggested that PLCζ might be used as a prognostic marker in specific cases of male infertility. The localisation patterns of PLCζ expression seemed to be affected by iatrogenic damage but intriguingly not by age. Collectively, the generated information could be implemented for the diagnosis of idiopathic infertility and towards the development of new therapeutic strategies against PLCζ deficiency. Given that, one in seven couples suffer from infertility, the findings of the study have important socio-economic implications.
