Search results
Results From The WOW.Com Content Network
Primordial germ cells are among the first lineages that are established in development [1] and they are the precursors for gametes. [2] It is thought that the process of primordial germ cell migration itself has been conserved rather than the specific mechanisms within it, as chemoattraction and repulsion seem to have been borrowed from blood cells, neurones, and the mesoderm. [1]
Germ cells migrating to the gonads may not reach that intended destination and a tumor can grow wherever they end up, but the exact cause is still unknown. These tumors can be benign or malignant. [23] On arrival at the gonad, primordial germ cells that do not properly differentiate may produce germ cell tumors of the ovary or testis in a mouse ...
Gonocytes are long-lived precursor germ cells responsible for the production of spermatogonial stem cells (SSCs). Gonocytes relate to both fetal and neonatal germ cells from the point at which they enter the testis primordial until they reach the base membrane at the seminiferous cords and differentiate.
Cleavage in most animals segregates cells containing germ plasm from other cells. The germ plasm effectively turns off gene expression to render the genome of the cell inert. Cells expressing germ plasm become primordial germ cells (PGCs) which will then give rise to the gametes. The germ line development in mammals, on the other hand, occurs ...
Cormlets of Watsonia meriana, an example of apomixis Clathria tuberosa, an example of a sponge that can grow indefinitely from somatic tissue and reconstitute itself from totipotent separated somatic cells. In biology and genetics, the germline is the population of a multicellular organism's cells that develop into germ cells.
These primordial germ cells (PGCs) multiply by mitosis and once they have reached the gonadal ridge they are called oogonia (diploid stem cells of the ovary). Once oogonia enter this area they attempt to associate with the other somatic cells, derived from both the peritoneum and mesonephros.
The gonads develop from three sources; the mesothelium, underlying mesenchyme and the primordial germ cells. Gonads start developing as a common primordium (an organ in the earliest stage of development), in the form of genital ridges , [ 7 ] at the sixth week, which are only later differentiated to male or female sex organs (except when they ...
Migration of primordial germ cells in the undifferentiated gonad: 6 10–15 Development of Müllerian ducts: 7 13–20 Differentiation of seminiferous tubules: 8 30 Regression of Müllerian ducts in male fetus: 8 32–35 Appearance of Leydig cells. First synthesis of testosterone: 9 43 Total regression of Müllerian ducts.