The phosphoinositide-3-kinase/Akt (PI3K/AKT) signaling pathway is crucial for Sertoli cell development and completing spermatogenesis. Its main role to promote proliferation inhibit apoptosis. Many factors activate the PI3K/AKT pathway, like hormones, such as follicle stimulating hormone (FSH), androgen, estrogen, insulin name a few. of these have receptors inside or on surface cells (SCs). Thi...

The spermatogonial stem cell (SSC) that supports spermatogenesis throughout adult life resides within the GFRα1-expressing A type undifferentiated spermatogonia. The decision to commit to spermatogenic differentiation coincides with the loss of GFRα1 and reciprocal gain of Ngn3 (Neurog3) expression. Through the analysis of the piRNA factor Miwi2 (Piwil4), we identify a novel population of Ngn3-...

Although the ability of engrafted stem cells to regenerate tissue has received much attention, the molecular mechanisms controlling regeneration are poorly understood. In the Drosophila male germline, local activation of the Janus kinase-signal transducer and activator of transcription (Jak-STAT) pathway maintains stem cells; germline stem cells lacking Jak-STAT signaling differentiate into spe...

Spermatogonial stem cells (SSCs) are one of the best studied types of stem cells with respect to cellular aspects and new data on the molecular pathways regulating their behavior now become available frequently. In non-primate mammals, SSCs have been identified as single spermatogonia that either selfrenew, by dividing into two new single spermatogonia, or differentiate by giving rise to a pair...

Geminin plays a critical role in cell cycle regulation by regulating DNA replication and serves as a transcriptional molecular switch that directs cell fate decisions. Spermatogonia lacking Geminin disappear during the initial wave of mitotic proliferation, while geminin is not required for meiotic progression of spermatocytes. It is unclear whether geminin plays a role in pre-meiotic DNA repli...

Aging and short photoperiod exposure induce germ cell apoptosis in the Syrian hamster; however, the specific germ cells affected and the molecular pathways triggered have not been elucidated. We analyzed germ cell apoptosis and the expression of the Fas/Fas-L system, Bcl-2 family, and p53 in aged and photoinhibited hamsters and compared with those young maintained in natural photoperiod. Aging ...

Dye coupling experiments were performed to determine whether the gap junctions connecting Sertoli cells with other Sertoli cells and different germ cell stages in rats showed functional variations. Chop loading of adult rat seminiferous tubules was conducted using fluorescent dextran controls and a variety of low-molecular-weight tracers (lucifer yellow, biotin-X-cadaverine, biotin cadaverine, ...

Different cellular events occur during spermatogenesis, and these include (i) mitosis for self-renewal of spermatogonia, (ii) differentiation of type A spermatogonia into type B and commitment of type B spermatogonia to develop into preleptotene primary spermatocytes, (iii) transit of preleptotene/leptotene spermatocytes across the blood-testis barrier in coordination with germ cell cycle progr...

BACKGROUND Although early development of testes appears normal in boys with Klinefelter syndrome (KS), spermatogonial stem cell (SSC) depletion occurs in mid puberty, leading to infertility. Cryopreservation of SSCs prior to stem cell loss is an option that is currently offered to boys who have to undergo gonadotoxic treatments. This study aimed to explore the possibility of preserving SSCs in ...