objective: today, special attention is paid to the use of zirconium dioxide nanoparticle (nano-zro2), a neutral bioceramic metal, particularly for drug and gene delivery in medicine. however, there are some reports implying that use of nano-zro2 is associated with cytotoxic effects like inhibiting the cell proliferation, dna damage and apoptosis. in the present study, we examined whether nano-z...

In most animals, primordial germ cell (PGC) specification and development depend on maternally provided cytoplasmic determinants that constitute the so-called germ plasm. Little is known about the role of germ plasm in vertebrate germ cell development, and its molecular mode of action remains elusive. While PGC specification in mammals occurs via different mechanisms, several germ plasm compone...

The continuous and steady supply of transient cell types such as skin, blood and gut depends crucially on the controlled proliferation of stem cells and their transit amplifying progeny. Although it is thought that signaling to and from support cells might play a key role in these processes, few signals that might mediate this interaction have been identified. During spermatogenesis in Drosophi...

Pluripotent embryonic stem cells are undifferentiated cells capable of proliferation and self-renewal and have the capacity to differentiate into all somatic cell types and the germ line. They provide an in vitro model of early embryonic differentiation and are a useful means for targeted manipulation of the genome. Pluripotent stem cells in the chick have been derived from stage X blastoderms ...

Transgenerational effects of environmental toxins require either a chromosomal or epigenetic alteration in the germ line. Transient exposure of a gestating female rat during the period of gonadal sex determination to the endocrine disruptors vinclozolin (an antiandrogenic compound) or methoxychlor (an estrogenic compound) induced an adult phenotype in the F1 generation of decreased spermatogeni...

Two components of the germ-line-specific P granules of the nematode Caenorhabditis elegans have been identified using polyclonal antibodies specific for each. Both components are putative germ-line RNA helicases (GLHs) that contain CCHC zinc fingers of the type found in the RNA-binding nucleocapsid proteins of retroviruses. The predicted GLH-1 protein has four CCHC fingers; GLH-2 has six. Both ...

elucidating the critical epigenetics events involved in differentiation and reprogramming of cells to primordial germ cells (pgcs) is among the interesting issues in stem cell research. here, i will talk about critical transcription factors and global hypomethylation in development of germ cells. evidence strongly suggests that the earliest pgcs emerging in the e7.25 mouse embryo epiblast have ...

objective: a number of studies have demonstrated the potential antitumor effects of saffron and its constituents on different malignant cells in vitro. it has been reported that a novel glycoconjugate isolated from corms and callus of saffron possesses cytotoxic activity against different tumor cellswith nitric oxide (no) production. these data suggest that the cytotoxic effect of saffron extra...

background: erythropoietin (epo) is a glycoprotein hormone function to regulate the production of red blood cells. deficiency of epo is known to cause anemia in chronically infected renal patients and they require regular blood transfusion. availability of recombinant epo has eliminated the need for blood transfusion and now it is extensively used for the treatment of anemia. glycosylation of e...

Spermatogonia are the male germ stem cells that continuously produce sperm for the next generation. Spermatogenesis is a complicated process that proceeds through mitotic phase of stem cell renewal and differentiation, meiotic phase, and postmeiotic phase of spermiogenesis. Full recapitulation of spermatogenesis in vitro has been impossible, as generation of normal spermatogonial stem cell line...