background: in most mammals, the testis is always maintained at a lower temperature than that in the abdomen, and exposure of the testis to body temperature causes degeneration of germ cells. objective: in this research, the long effect of heat exposure on sperm parameters and microstructure of mouse testis were investigated. cryptorchid mouse were induced by exposure to abdominal heat. materia...

A dichotomy exists between germ and somatic cells in most organisms, such that somatic cell lineages proliferate for a single generation, whereas the germ cell lineage has the capacity to proliferate from one generation to the next, indefinitely. Several theories have been proposed to explain the unlimited replicative life span of germ cells, including the elimination of damaged germ cells by a...

Differentiation of germ cells into male gonocytes or female oocytes is a central event in sexual reproduction. Proliferation and differentiation of fetal germ cells depend on the sex of the embryo. In male mouse embryos, germ cell proliferation is regulated by the RNA helicase Mouse Vasa homolog gene and factors synthesized by the somatic Sertoli cells promote gonocyte differentiation. In the f...

Segregation of the germ line from the soma is an essential event for transmission of genetic information across generations in all sexually reproducing animals. Although some well-studied systems such as Drosophila and Xenopus usematernally inherited germ determinants to specify germ cells, most animals, including mice, appear to utilize zygotic inductive cell signals to specify germ cells duri...

One of the major decisions that germ cells make during their development is whether to differentiate into oocytes or sperm. In mice, the germ cells' decision to develop as male or female depends on sex-determining signalling molecules in the embryonic gonadal environment rather than the sex chromosome constitution of the germ cells themselves. In response to these sex-determining cues, germ cel...

During germ cell development, epigenetic modifications undergo extensive remodeling. Abnormal epigenetic modifications usually result in germ cell loss and reproductive defect. Prmt5 (Protein arginine methyltransferase 5) encodes a protein arginine methyltransferase which has been demonstrated to play important roles in germ cell development during embryonic stages. In the present study, we fou...

embryonic stem cells (escs) are undifferentiated cells which are typically derived from the inner cell mass of a blastocyst-stage embryo. in culture, these cells have the capacity to self-renew in an undifferentiated state but also may differentiate into cell types representing the three embryonic germ lineages, thus revealing their pluripotent potential. these cells could be of value for creat...

Several inducers have been used to differentiate embryonic stem cells (ESCs) into male germ cells but the induction process has been inefficient. To solve the problem of low efficiency of inducer for ESCs differentiation into male germ cells, all-trans retinoic acid (ATRA), Am80(the retinoic acid receptor agonist), and estradiol (E2) was used to induce ESCs to differentiate into male germ cells...

Early in development, a part of the embryo is set aside to become the germ cell lineage that will ultimately differentiate to form sperm and eggs and transmit genetic information to the next generation. Men with deletions encompassing the Y-chromosome DAZ genes have few or no germ cells but are otherwise healthy, indicating they harbor specific defects in formation or maintenance of germ cells....

The mechanisms underlying human germ cell development are largely unknown, partly due to the scarcity of primordial germ cells and the inaccessibility of the human germline to genetic analysis. Human embryonic stem cells can differentiate to germ cells in vitro and can be genetically modified to study the genetic requirements for germ cell development. Here, we studied NANOS3 and DAZL, which ha...