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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]
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 by induction and not by an endogenous germ plasm (see reference 6.).
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 ...
During early embryonic development, cells from the dorsal endoderm of the yolk sac migrate along the hindgut to the gonadal ridge. 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).
They differentiate in the gonads from primordial germ cells into gametogonia, which develop into gametocytes, which develop into the final gametes. [1] This process is known as gametogenesis. Germ cells pass on genetic material through the process of sexual reproduction. This includes fertilization, recombination and meiosis. These processes ...
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. At the time of gastrulation, certain cells are set aside for later gamete development. These cells are called post migratory germ cells (PGCs).
In the mouse, primordial germ cells arise from the inner cell mass (the epiblast) as a result of extensive genome-wide reprogramming. [22] Reprogramming involves global DNA demethylation facilitated by the DNA base excision repair pathway as well as chromatin reorganization, and results in cellular totipotency. [23] [20]
In mammalian germ cell development, sexually dimorphic gametes differentiates into primordial germ cells from pluripotent cells during initial mammalian development. [2] Males and females of a species that reproduce sexually have different forms of gametogenesis: spermatogenesis (male): Immature germ cells are produced in a man's testes. To ...