The underlying primary damage to the testis caused by chemotherapeutic regimens during childhood is largely unknown. Xenografting of monkey testes was successfully applied in maturation of juvenile testis to the point of complete spermatogenesis. This allows us to manipulate developing primate testis without direct treatment of patients. This new model is validated establishing the effects of c...

Background The present study was designed to evaluate the survival and proliferation of spermatogonial stem cells from cryptorchid mouse testis in co-culture system over a 3 weeks period. MaterialsAndMethods Sertoli and spermatogonial cells were isolated from bilateral cryptorchid mouse model testes. Isolated spermatogonial cells were co-cultured with Sertoli cells in minimal essential medium (...

BACKGROUND A key step in studying the biology of spermatogonia is to determine their global gene expression profile. However, disassociation of these cells from the testis may alter their profile to a considerable degree. To characterize the molecular phenotype of human spermatogonia, including spermatogonial stem cells (SSCs), within their cognate microenvironment, a rare subtype of human defe...

Undifferentiated spermatogonia comprise a pool of stem cells and progenitor cells that show heterogeneous expression of markers, including the cell surface receptor GFRα1. Technical challenges in isolation of GFRα1+ versus GFRα1- undifferentiated spermatogonia have precluded the comparative molecular characterization of these subpopulations and their functional evaluation as stem cells. Here, w...

The pattern of ribonucleic acid synthesis during germ cell development, from the stem cell to the mature spermatid, was studied in the mouse testis, by using uridine-H(3) or cytidine-H(3) labeling and autoradiography. Incorporation of tritiated precursors into the RNA occurs in spermatogonia, resting primary spermatocytes (RPS), throughout the second half of pachytene stage up to early diploten...

The commonly applied classification systems of fish gonad maturity divide the maturation process into certain stages. However, the scales do not entirely reflect the continuity of the maturation process. Based on light microscope observations, the paper describes a comprehensive pattern of testicular transformations during maturation. The study was carried out on precocious underyearling and 1-...

Infertility is a serious late effect in childhood cancer survivors. Little is known about acute irradiation effects in immature primate testis. Radiation defects have previously only been studied in postpubertal primates. Here we use the juvenile rhesus monkey as a preclinical model. We expose fragments of testicular tissue to 0, 0.5, 1.0, and 4.0 Gy irradiation in vitro. We then maintain the f...

Gonadal differentiation is tightly regulated by the initial sex determining gene and the downstream sex-related genes in vertebrates. However, sex change in fish can alter the sexual fate from one sex to the other. Chemical-induced maleness in the protogynous orange-spotted grouper is transient, and a reversible sex change occurs after the chemical treatment is withdrawn. We used these characte...

I n males, sperm production begins at puberty and lasts throughout reproductive life. This implies that a population of germ stem cells/progenitors must be maintained, amplified and differentiate throughout life to enable the continuous supply of sperm. Spermatogenesis is indeed divided into three phases: a proliferative phase, a meiotic phase and a postmeiotic spermiogenic phase. In the prolif...