In many organisms, the primordial germ cells have to migrate from the position where they are specified towards the developing gonad where they generate gametes. Extensive studies of the migration of primordial germ cells in Drosophila, mouse, chick and Xenopus have identified somatic tissues important for this process and demonstrated a role for specific molecules in directing the cells toward...

Background: In avian species, the germ line stem cell population arises outside of the embryonic gonad and proceeds on a circuitous migration to the germinal epithelium. Specifically, in the avian embryo, the process of germ line stem cell migration proceeds through a series of active and passive migratory phases. The germline stem cells or primordial germ cells (PGCs) located in the epiblast o...

Mouse primordial germ cells express tissue non-specific alkaline phosphatase (TNAP) during development, but the widespread expression of another alkaline phosphatase gene in the early embryo limits the potential use of this marker to trace germ cells. To attempt to identify germ cells at all stages during embryonic development and to understand the role of TNAP in germ cell ontogeny, mice carry...

BACKGROUND In mammalian females, reproductive capacity is determined by the size of the primordial follicle pool. During embryogenesis, oogonia divide mitotically but cytokinesis is incomplete so oogonia remain connected in germ cell cysts. Oogonia begin to enter meiosis at 13.5 days postcoitum in the mouse and over several days, oocytes progress through the stages of meiotic prophase I arresti...

Notch signaling directs cell fate during embryogenesis by influencing cell proliferation, differentiation, and apoptosis. Notch genes are expressed in the adult mouse ovary, and roles for Notch in regulating folliculogenesis are beginning to emerge from mouse genetic models. We investigated how Notch signaling might influence the formation of primordial follicles. Follicle assembly takes place ...

Objective(s): The present day challenge is how to obtain germ cells from stem cells to treat patients with cancer and infertility. Much more efforts have been made to develop a procedure for attaining germ cells in vitro. Recently, human umbilical cord-derived mesenchymal stem cells (HUMSCs) have been introduced with higher efficacy for differentiation. In this work, we tried to explore the eff...

The initial effect of u.v. irradiation of the vegetal pole was to inhibit cleavage in the vegetal hemisphere although karyokinesis was not substantially affected. In this way a syncytium formed in the vegetal hemisphere which broke down into individual cells some time between morula and late blastula. The movement of the germ plasm from the peripheral cortical regions into the interior of the e...