[Structure and role of protamines 1 and 2 in spermatogenesis and male infertility]

In the last decade the abnormalities in male infertility became the main problem of more than 50% couples. The main reasons of male infertility are abnormal gonadotropin releasing hormone (GnRH) secretion, pituitary gland diseases and presence of testicular genetic defects. The male infertility also may result from chemotherapy, radiotherapy and viral infections. The main genetic factors responsible for male infertility encompass the mutations of genes, which encode important factors of spermatogenesis. Recently mRNAs of numerous genes have been identified in spermatozoa. The first transcripts found in spermatozoa included protamine 1 and 2 (PRM1 and PRM2). Protamines are basic polypeptides, which form complex with DNA in spermatids and spermatozoa. Structure of PRM1 and PRM2 genes and function of these proteins suggest the possible relationship between of protamines expression disorders and male infertility. The PRM1, PRM2 and transition proteins 1 and 2 (TP1 and TP2) play important role in DNA condensation. We attempted to present current knowledge regarding structure and expression regulation of PRM1 and PRM2 genes. We also discussed the effect of disorders of PRM1 and PRM2 expression on male infertility.