Background The piwi family genes are highly conserved during evolution and play a crucial role in stem cell self-renewal, gametogenesis, and RNA interference in diverse organisms ranging from Arabidopsis to humans. Piwil2, also known as Hili, is one of the four human homologues of piwi. Piwil2 was found in germ cells of adult testis, suggesting that this gene functions in spermatogonial stem ce...

testicular germ cell tumor (tgct) is the most solid tumor in 20-40 years old man. tgct account for 95% of testicular tumors and represent a unique type of human cancer from several different perspectives. tgct arise by transformation of germ cells. the transformed germ cells exhibit ploripotentially to differentiate into embryonic. extra-embryonic, and somatic tissue types, and are highly sensi...

Background: Nicotine is considered as one of the most agents in cigarette smoking and has side effects on many organs and body systems such as reproductive tract. Nicotine can induce sub fertility or infertility both in males and females. The aim of this study was to evaluate the proliferative activity of adult mouse male germ cells following treatment with different doses of nicotine. Material...

Recently, cell signaling has been shown to be required for the formation of germ cells in the mouse embryo, direct observation of germ cell migration in living mouse embryos has been achieved, novel genes that control germ-cell migration have been identified in Drosophila, and the roles of many components of germ plasm in several species have become clearer.

background: non obstructive azoospermia (noa) is one of the causes of male infertility in which spermatogenesis process is disturbed. recent studies suggested the possible role of endothelial nitric oxide synthase (enos) in spermatogenesis process. objective: the aim of the present study is to evaluate the expression of enos in human testicular tissue in men with noa and men with normal spermat...

spermatogonial stem cell (ssc) technologies provide multiple opportunities for research in the field of biotechnology and regenerative medicine. the therapeutic use of embryonic stem cells (escs) is restricted due to severe ethical and immunological concerns. therefore, we need a new pluripotent cell type. despite well-known role of germ cells in the gametogenesis, some facts apparently show th...