PKnox1 (also known as Prep1) belongs to the TALE family of homeodomain transcription factors that are critical for regulating growth and differentiation during embryonic and postnatal development in vertebrates. We demonstrate here that PKnox1 is required for adult spermatogenesis in a germ cell-intrinsic manner. Tamoxifen-mediated PKnox1 loss in the adult testes, as well as its germ cell-speci...

Studies on circaannual changes in reproduction of Rainbow trout (Oncorhynchus mykiss), an economically important fish of Kashmir have been carried out. The variations in testicular structure and function of rainbow trout were studied during the present investigation. Morphometric and gravimetric data revealed four distinct reproductive phases viz. (I) Resting or Spent stage (II) Maturation stag...

The hormones that regulate spermatogonial development are ill defined, in part due to lack of appropriate experimental models. The photoinhibited hamster model provides a rich source of spermatogonia, thus making it an ideal model to study their control. This study aimed to assess the effects of FSH, in the absence of testosterone, on the reinitiation of Sertoli cell and spermatogonial developm...

Vitamin A is instrumental to mammalian reproduction. Its metabolite, retinoic acid (RA), acts in a hormone-like manner through binding to and activating three nuclear receptor isotypes, RA receptor (RAR)α (RARA), RARβ, and RARγ (RARG). Here, we show that 1) RARG is expressed by A aligned (A(al)) spermatogonia, as well as during the transition from A(al) to A(1) spermatogonia, which is known to ...

For the purpose of clarifying the histopathological effects of methotrexate (MTX) on medaka testes, wild-type and homogenic p53-deficient male medaka at 4 to 6 months post-hatching were exposed to 0.25 mg/ml of MTX for 96 h with histopathological examination of testes at 24, 48, 72 and 96 h. At 72 and 96 h after the start of MTX exposure, numerous apoptotic cells were observed in the spermatogo...

Mammalian spermatogenesis is maintained by spermatogonial stem cells (SSCs). However, since evidentiary assays and unequivocal markers are still missing in non-human primates (NHPs) and man, the identity of primate SSCs is unknown. In contrast, in mice, germ cell transplantation studies have functionally demonstrated the presence of SSCs. LIN28 is an RNA-binding pluripotent stem cell factor, wh...

Glial cell-line-derived neurotropic factor (GDNF) and its receptors glial cell-line-derived neurotropic factor alpha (GFR1alpha) and rearranged during transformation (RET) have been localized in the rat testis during postnatal development. The three mRNAs, and GDNF and GFR1alpha proteins were detected in testis extracts from 1- to 90-day-old rats by reverse transcriptase PCR and Western blottin...

Within the testis, Sertoli-cell is the primary target of pituitary FSH. Several growth factors have been described to be produced specifically by Sertoli cells and modulate male germ cell development through paracrine mechanisms. Some have been shown to act directly on spermatogonia such as GDNF, which acts on self-renewal of spermatogonial stem cells (SSCs) while inhibiting their differentiati...

objective: testicular cell transplantation has been widely used to investigate the restoration of fertility in rodent models. in this research we apply transplantation as a treatment method in the cryptorchid model and compare this method with orchidopexy, which is the routine treatment for this problem. we studied the controversial effects of treatment on the number of germ cells and other mor...

Spermatogenesis is sensitive to the chemotherapeutic drug cyclophosphamide, which decreases the patients' sperm count. Since the recovery of fertility is dependent on regeneration from stem cells, in the present study we evaluated the ability of cyclophosphamide-exposed stem spermatogonia from mice to regenerate spermatogenesis in situ and after transplantation. When seven doses of cyclophospha...