oa Dynamins, Spermatogenesis and Contraceptive Development

Dynamins are large GTPases of ∼100 kDa known to participate in endocytosis and interact with the actin-based cytoskeletal network in multiple tissues. Recent studies have shown that dynamins play a critical role in the internalization of integral membrane proteins via either clathrin-mediated or clathrin-independent endocytosis. Furthermore, recent studies have shown that dynamin II interacts with junctional complex adaptors, namely ZO-1 and β-catenin, at the blood-testis barrier in the seminiferous epithelium of adult rat testes. This interaction may be responsible for pulling away tight junction- and adherens junction-based protein complexes, thereby facilitating blood-testis barrier opening to permit preleptotene and leptotene spermatocyte migration, which is a critical event in spermatogenesis occurring at stage VIII of the seminiferous epithelial cycle. In this short review, we highlight some of the latest findings on dynamins in the field, and discuss how this information can be used to further expand the functional studies to tackle the role of dynamins in spermatogenesis. It is likely that dynamins per se or their interacting protein partners can become a target for male contraceptive research to compromise spermatogenesis, leading to transient male infertility without perturbing the hypothalamic-pituitary-testicular axis.