DAAM1 and PREP are involved in human spermatogenesis.

During differentiation of the male gamete, a massive remodelling in the shape and architecture of all the cells in the seminiferous epithelium occurs. The cytoskeleton, as well as many associated proteins, plays a pivotal role in this process. To better characterize the factors involved, we analysed two proteins: the formin Dishevelled-Associated Activator of Morphogenesis 1 (DAAM1), which participates in the regulation of actin polymerization, and the protease Prolyl Endopeptidase (PREP), engaged in microtubule-associated processes. In our previous works we demonstrated their involvement in cytoskeletal dynamics necessary for a proper post-natal development of the rat testis. Here, we used samples of human testicular tissue obtained from infertile men by Testicular Sperm Extraction and spermatozoa of asthenoteratozoospermic patients. By Western blot and immunofluorescent analysis, we found that DAAM1 and PREP expression and localization is impaired both in the testis and in spermatozoa, and in particular in the midpiece as well as in the principal and end pieces of flagella, as compared to spermatozoa of normospermic men. Our results provide new knowledge to clarify the dynamics of spermatogenesis, raising the possibility of using DAAM1 and PREP proteins as new markers for normal fertility.