Primordial germ cells (PGCs) are germline stem cells that give rise to gametes in vertebrates. They originate outside the embryo very early in development and migrate by a well-defined route into the genital ridges. During early embryogenesis in mammals, the PGCs are observed in an extra-embryonic region near the yolk sac, translocate to the endodermal epithelium of the hindgut as embryogenesis...

A fundamental yet unexplored question in stem cell biology is how the fate of tissue stem cells is initially determined during development. In Drosophila, germline stem cells (GSCs) descend from a subset of primordial germ cells (PGCs) at the onset of oogenesis. GSC determination may occur at the onset of oogenesis when a subset of PGCs is induced to become GSCs by contacting niche cells. Alter...

In order to determine the origin and migration of ukigori primordial germ cells (PGCs), we observed the aggregation of vasa mRNA by whole mount in situ hybridization. To observe PGC migration in the germ layers, we analyzed HE-stained paraffin sections. The germ line lineages were derived from the edge of the first, second and third cleavage furrows. During subsequent cleavages, vasa mRNA aggre...

The aim of this study was to investigate the spatiotemporal development of autonomic nerve fibers and primordial germ cells (PGCs) along their migratory route from the dorsal mesentery to the gonadal ridges in human embryos using immunohistochemical markers and electron microscopy. Autonomic nerve fibers in the dorsal mesentery, the pre-aortic and para-aortic plexuses and in the gonadal ridge w...

Primordial germ cells (PGCs) give rise to both eggs and sperm via complex maturational processes that require both cell migration and proliferation. However, little is known about the genes controlling gamete formation during the early stages of PGC development. Although several mutations are known to severely reduce the number of PGCs reaching and populating the genital ridges, the molecular i...

During primordial germ cell (PGC) development, epigenetic reprogramming events represented by X chromosome reactivation and erasure of genomic imprinting are known to occur. Although precise timing is not given, X reactivation is thought to take place over a short period of time just before initiation of meiosis. Here, we show that the cessation of Xist expression commences in nascent PGCs, and...

Inheritance depends on the expansion of a small number of primordial germ cells (PGCs) in the early embryo. Proliferation of mammalian PGCs is concurrent with their movement through changing microenvironments; however, mechanisms coordinating these conflicting processes remain unclear. Here, we find that PGC proliferation varies by location rather than embryonic age. Ror2 and Wnt5a mutants with...

Connexin 43 knockout (Cx43alpha1KO) mice exhibit germ cell deficiency, but the underlying cause for the germ cell defect was unknown. Using an Oct4-GFP reporter transgene, we tracked the distribution and migration of primordial germ cells (PGCs) in the Cx43alpha1KO mouse embryo. Analysis with dye injections showed PGCs are gap-junction-communication competent, with dye coupling being markedly r...

In Xenopus laevis tadpoles, between stages 44 and 49 (Nieuwkoop & Faber, 1956), the primordial germ cells (PGCs) migrate from the dorsal mesentery of the gut to the site of the presumptive GD gonadal ridge. This paper describes the process at the light- and electronmicroscope levels. The PGCs in the mesentery, which at first are very large and yolk-laden, seem to lie entirely within the cellula...

The migration of zebrafish primordial germ cells (PGCs) is directed by SDF-1a and serves as a model for long-range chemokine-guided cell migration. Whereas the development and migration of zebrafish PGCs have been studied in great detail starting at mid-gastrulation stages when the cells exhibit guided active migration [7-8 hours post fertilization (hpf)], earlier stages have not yet been exami...