A histological study of the testes of stags shot in autumn (sexual season) and spring (quiescent period) indicated that the 3-fold increase in testicular size observed in the autumn was accompanied by increases in nearly all features studied (volumes of intertubular tissue, Leydig cells, blood vessels and peritubular cells; diameter and length of seminiferous tubules; the number of A1 spermatog...

Spermatogenesis is a complex series of cellular changes leading to the formation of haploid male gametes (spermatozoa) and includes mitotic, meiotic and post-meiotic phases. Spermatogonial stem cells (SSCs) are essential for the continuous lifelong production of spermatozoa. Spermatogenesis is initiated when SSC is triggered to undergo mitosis that gives rise to progenitors, which further diffe...

Spermatogenesis, the process by which haploid sperm cells are produced from a diploid precursor cell, is essential for sexual reproduction. Here, we report that RING-finger protein 138 (Rnf138) is highly expressed in testes, especially in spermatogonia and spermatocytes. The role of Rnf138 in spermatogenesis was examined using a Rnf138-knockout mouse model. Rnf138 deficiency resulted in increas...

As part of a collaborative effort to evaluate whether effects on male reproductive organs of chemicals can be detected within two-week in toxicity studies, eight-week-old male Sprague-Dawley rats were given a single oral administration of 100 mg/kg of Cyclophosphamide (Cp), and sacrificed at 1, 3, 7 and 14 days thereafter. The numbers of seminiferous epithelial cells were counted in the seminif...

Interest in spermatogonia has grown in recent years as a result of exciting developments in stem cell research in general and the development of new research tools allowing the isolation, culture and transplantation of these cells. This review focuses on the methodological breakthroughs and highlights the recent findings that have substantially increased understanding of spermatogonial physiolo...

Retinoic acid is like a steroid hormone that plays a role in embryo formation, proliferation of spermatogonia cells, ephitelial cells differentiation and organogenesis. Retinoic acid can influences seminiferous tubule formation during embryonic testis development and also play a role in the regulation of ovarian function and female reproductive tract by suppressing the hormones FSH receptor exp...

Defective mini-puberty results in insufficient testosterone secretion that impairs the differentiation of gonocytes into dark-type (Ad) spermatogonia. The differentiation of gonocytes into Ad spermatogonia can be induced by administration of the gonadotropin-releasing hormone agonist, GnRHa (Buserelin, INN)). Nothing is known about the mechanism that underlies successful GnRHa treatment in the ...

Sustained spermatogenesis in adult males and fertility recovery following germ cell depletion are dependent on undifferentiated spermatogonia. We previously demonstrated a key role for the transcription factor SALL4 in spermatogonial differentiation. However, whether SALL4 has broader roles within spermatogonia remains unclear despite its ability to co-regulate genes with PLZF, a transcription ...

The first step in established spermatogenesis is the production of progenitor cells by the stem cell population. The progenitor cells (undifferentiated A spermatogonia) expand in number via the formation of syncytial chains by mitosis. The mechanism by which these progenitor cells commit to meiosis and spermatogenesis is tightly controlled and results in complex morphological organization all o...

Spermatogonial stem cells (SSCs) represent a unique population of germ cells with self-renewal potential. Although reactive oxygen species (ROS) are considered toxic to germ cells, we recently showed that moderate levels of ROS are required for SSC self-renewal and that Nox1 is involved in ROS generation. In this study, we showed that self-renewal factor treatment induces Nox3 to trigger SSC se...