Researchers identify the key sperm proteins for the development of the embryo

Beyond their aim, which is to advance in the knowledge of the processes of cell division preceding the formation of a human life, the work of Eugin and tCRG professionals stands out for the technique used. The researchers used sperm samples whose heads had been removed before injecting them into oocytes and studying the function of the previously mentioned proteins.

The decision to use this technique complies with the current legal framework, which is that Law 14/2006 on assisted human reproduction prevents the fertilisation of eggs for research purposes. As pointed out by Dr. Montserrat Barragan, head of Eugin's laboratory at PCB and co-author of this study whose first author is Farners Amargant, a researcher at CRG and Eugin. "We know that there is a study dating back from ten years ago that used only sperm tails, but it is true that it is an infrequently used technique," she says.

30% of fertilised eggs in assisted reproduction processes stop developing in the early stages of cell division. This leads scientists to believe that the functional defects in the sperm cell could be responsible for these failures. "Our results suggest that one of the key and exclusive functions of sperm in fertilisation is to provide the centrioles, which are fundamental for the formation of the centrosome in the zygote. The centrosome is an essential organelle for cell division and, consequently, for embryonic development", explains Isabelle Vernos, ICREA research professor at the CRG and co-leader of this study. "Identifying these key proteins for the formation of the centrosome helps us to understand how the zygote is organized in the early stages of its development", concludes the researcher.

These proteins are only found in the middle piece of a sperm cell, between the neck and tail. Hence, it was not essential to keep its head for this investigation. After a proteomic study of several sperm samples carried out in the Proteomics Unit of the CRG and the UPF, the researchers were able to identify 288 proteins involved in the formation of the functional centrosome. "Our study contributes towards the advancement in our knowledge of cell division processes and, specifically, in the knowledge of the functions and structure of sperm. But we must continue investigating", says Dr. Montserrat Barragan.

This work is the result of the close collaboration between the Eugin Group and the CRG. This is a partnership that began four years ago as a result of an internal initiative by the CRG, to promote multidisciplinary research more geared towards a clinical application, and which was strengthened last March with the signing of a partnership framework agreement in molecular research applied to assisted reproduction. With this alliance, the research potential of the CRG joins forces with the Eugin group's vast experience in assisted reproduction and in treating patients to promote interdisciplinarity and contributes towards scientific knowledge that benefits society.