Abstract: Sperm functional maturation refers to the gradual ability obtaining of flagellar motility and fertilization during epididymal transition. Recently, with the development and application of cutting-edge techniques of gene function study such as gene knockout and gene over-, the pivotal role of the flagellar protein involved in structure changes and modification during sperm maturation have been revealed. For instance, glyceraldehyde 3-phosphate dehydrogenase (GAPDH) significantly increases in amount and binds to fibrous sheath during epididymal transition, involving in glycolysis and energy production. Besides, a kinase anchoring protein4 (AKAP4), a protein associated with flagellar motility and bound to the same site as GAPDH, undergoes phosphorylation in epididymis. Herein, we review the latest research advances in flagellar proteins about their changes in quantity, structure and function in order to elucidate the physiological and pathological mechanisms for sperm motility and clinical asthenozoospermia respectively, and to explore male contraceptive vaccine which can block sperm motility as well.

Key words: Spermatozoa, Sperm Maturation, Epididymis, Flagellar Protein