A seamless trespass: germ cell migration across the seminiferous epithelium during spermatogenesis

During spermatogenesis, preleptotene spermatocytes traverse the blood–testis barrier (BTB) in the seminiferous epithelium, which is reminiscent of viral pathogens breaking through the tight junctions of host epithelial cells. The process also closely resembles the migration of leukocytes across endothelial tight junctions to reach inflammation sites. Cell adhesion molecules of the immunoglobulin superfamily (e.g., JAM/CAR/nectin) participate in germ cell migration by conferring transient adhesion between Sertoli and germ cells through homophilic and heterophilic interactions. The same molecules also comprise the junctional complexes at the BTB. Interestingly, JAM/CAR/nectin molecules mediate virus uptake and leukocyte transmigration in strikingly similar manners. It is likely that the strategy used by viruses and leukocytes to break through junctional barriers is used by germ cells to open up the inter–Sertoli cell junctions. In associating these diverse cellular events, we highlight the “guiding” role of JAM/CAR/nectin molecules for germ cell passage. Knowledge on viral invasion and leukocyte transmigration has also shed insights into germ cell movement during spermatogenesis

Drug transporters in spermatogenesis: A re-evaluation of recent data on P-glycoprotein

Drug transporters are integral membrane proteins expressed by a variety of organs, including the liver, kidney, small intestine and testis, and they are generally known to mediate drug or xenobiotic transport into and out of cells. Previous studies have also reported the presence of several drug transporters at blood-tissue barriers where they are thought to protect organs from harmful agents. In this editorial, we briefly discuss and re-evaluate recent findings that show P-glycoprotein, an efflux pump, to function at the blood-testis barrier. We also put forth a mechanistic model, hoping this information will form a strong basis for future studies

Fantastic Behavior of High-TC Superconductor Junctions: Tunable Superconductivity

Carrier injection performed in oxygen-deficient YBa2Cu3O7(YBCO) hetero-structure junctions exhibited tunable resistance that was entirely different with behaviors of semiconductor devices. Tunable superconductivity in YBCO junctions, increasing over 20 K in transition temperature, has achieved by using electric processes. To our knowledge, this is the first observation that intrinsic property of high TC superconductors superconductivity can be adjusted as tunable functional parameters of devices. The fantastic phenomenon caused by carrier injection was discussed based on a proposed charge carrier self-trapping model and BCS theory.Comment: 5 pages, 4 figure

Filamin A: A regulator of blood-testis barrier assembly during post-natal development

Filamins are a family of actin-binding proteins composed of filamin A, B and C. Besides of their ability to induce perpendicular branching of F-actin filaments via their actin binding domains near the N-terminus, filamins can regulate multiple cellular functions because of their unique ability to recruit more than 90 protein binding partners to their primary sequences which are having highly diversified cellular functions. However, this family of proteins has not been examined in the testis until recently. Herein, we highlight recent findings in the field regarding the role of these proteins in cell epithelia, and based on recent data in the testis regarding their role on spermatogenesis, this review provides the basis for future functional studies