Earlier studies have shown adjudin to cause aspermatogenesis by depleting virtually all germ cells from the seminiferous epithelium, leading to transient infertility; spermatogenesis and fertility were re-established several weeks later after germ cell proliferation and differentiation were reinitiated by spermatogonia. While adjudin is known to exert its initial effects at the apical ectoplasm...

Viviparous lizards living in cold climate of high altitude often exhibit atypical reproductive cycles, in which mating and fertilization occur synchronously and annually with parturition occurring at the end of the year. Nevertheless, detailed case studies on atypical reproductive cycles are few. Using anatomical data combined with behavioral observations, we examined the reproductive cycle of ...

Tubulobulbar complexes (TBCs) are actin-based structures that help establish close contact between Sertoli-Sertoli cells or Sertoli-mature germ cells (spermatids) in the seminiferous tubules of the testes. They are actin-rich push-through devices that eliminate excess spermatid cytoplasm and prepare mature spermatids for release into the tubular lumen. Just prior to spermiation, the elongated s...

Intracellular calcium signaling is critical for initiating and sustaining diverse cellular functions including transcription, synaptic signaling, muscle contraction, apoptosis and fertilization. Trans-membrane 203 (TMEM203) was identified here in cDNA overexpression screens for proteins capable of modulating intracellular calcium levels using activation of a calcium/calcineurin regulated transc...

In mature male snakes and lizards, a distal portion of the nephron is hypertrophied in relation to its appearance in females and immature males. This sexual segment of the male kidney apparently provides seminal fluid that is mixed with sperm and released into the female cloaca during copulation. In this article, we provide the first study at the ultrastructural level of seasonal variation in t...

Introduction: Cyclophosphamide (CP) is used for the treatment of various cancers. In spite of its therapeutic importance, a wide range of adverse effects such as reproductive toxicity has been observed following the administration of this drug in human and experimental animals. In the current study, we have investigated the adverse effects of CP on morphology and histology of testis rats. Metho...

AIM To understand the biological functions of the ectoplasmic specializations between Sertoli cells and maturing spermatids in seminiferous epithelia. METHODS In order to disrupt the function of the ectoplasmic specializations, nectin-2, which is expressed at the specialization, was neutralized with anti-nectin-2 antibody micro-injected into the lumen of the mouse seminiferous tubule. Anti-ne...

Cellular events that occur across the seminiferous epithelium in the mammalian testis during spermatogenesis are tightly coordinated by biologically active peptides released from laminin chains. Laminin-γ3 domain IV is released at the apical ectoplasmic specialization during spermiation and mediates restructuring of the blood-testis barrier, which facilitates the transit of preleptotene spermat...

Liver serine/threonine kinase B1 (LKB1) is a tumor suppressor associated with the pathogenesis of Peutz-Jeghers syndrome. Affected males are at increased risk of developing Sertoli cell tumors and display defective spermatogenesis. Male mice lacking the short isoform (Lkb1S) of Lkb1 were sterile and exhibited abnormal spermiogenesis. In addition to the short isoform, the long isoform of Lkb1 (L...

Current male hormonal contraceptive (MHC) regimens act at various levels within the hypothalamic pituitary testicular axis, principally to induce the withdrawal of the pituitary gonadotrophins and in turn intratesticular androgen production and spermatogenesis. Azoospermia or severe oligozoospermia result from the inhibition of spermatogonial maturation and sperm release (spermiation). All regi...