ABSTRACT
Oligoasthenozoospermia, teratozoospermia or low sperm motility is the main cause of male infertility. Low sperm motility can be induced by abnormalities of the sperm tail structure and sperm function. The outer dense fiber protein 2 (ODF2) is a protein fiber maintaining cytoskeleton, as a major component of the mammalian sperm tail and centrosome, and its abnormality is closely related to asthenospermia. Recent studies indicate that ODF2 includes many proteins of the same name and homologous splices located in the sperm centrosomes and spindles of cleaved-embryos, necessary for animal ciliogenesis and associated with sperm capacitation. The features of ODF2 indicate that it is not a single-structural protein. This paper reviews the known functions of ODF2, paving a ground for further studies of the relationship between the ODF2 protein and fertilization.