Genome-wide DNA demethylation, including the erasure of genome imprints, in primordial germ cells (PGCs) is a critical first step to creating a totipotent epigenome in the germ line. We show here that, contrary to the prevailing model emphasizing active DNA demethylation, imprint erasure in mouse PGCs occurs in a manner largely consistent with replication-coupled passive DNA demethylation: PGCs...

Background: Primordial germ cell (PGC) specification is a universal process across animals, but the molecular mechanisms specifying PGCs are remarkably diverse. In Drosophila, PGCs are specified bymaternally provided, asymmetrically localized cytoplasmic factors (germ plasm). In contrast, historical literature on most other arthropods reports that PGCs arise from mesoderm during midembryogenesi...

The migration of the PGCs from a stage XIII epiblast into the germinal crescent of a stage 10 chick blastoderm was experimentally investigated. Considerable numbers of PGCs start to come down from the epiblastic layer at stage XII-XIII and continue to do so in relatively smaller numbers until stage 6. The earliest PGCs land on the primary hypoblast and probably are carried by it into the GC. Th...

Microglial activation may play a role in the pathogenesis of Huntington's disease (HD). Using 11C-(R)-PK11195 (PK) positron emission tomography (PET), we investigated microglial activation in HD presymptomatic gene carriers (PGCs), its relationship with striatal neuronal dysfunction measured with 11C-raclopride (RAC) PET, and the role of PK PET as a possible marker of subclinical disease progre...

Trophectoderm cells are the foremost embryonic cells to differentiate with prospective stem-cell properties. In the current study, we aimed at improving the current approach for trophoblast culture by using granulosa cells as feeders. Porcine granulosa cells (PGCs) compared to the conventional mouse embryonic fibroblasts (MEFs) were used to grow trophectoderm cells from hatched bovine blastocys...

Correlation of the number of primordial germ cells (PGCs) at stage 47 with the amount of germ plasm at the 8-cell stage and with the number of the germ-plasm-containing cells (GPCCs) was analysed using two different laboratory-raised colonies of Xenopus laevis, HD and J groups. The average number of PGCs in J group tadpoles was significantly larger than that in HD group tadpoles. The amount of ...

We have isolated migrating primordial germ cells (PGCs) from 10.5-day mouse embryos and studied their behaviour when cultured on a mouse embryo fibroblast (STO) cell line. Living and fixed PGCs were identified by fluorescent labelling with a monoclonal antibody specific for PGCs in the culture system used. The behaviour of the cells was studied using interference reflexion microscopy (IRM) and ...

A technique to identify and isolate live fish primordial germ cells (PGCs) has not been established, in spite of the importance of purified germ cells for molecular and cellular studies. In rainbow trout, the distribution of vasa transcripts is restricted to the germ cell lineage, making this transcript a useful indicator of PGCs. Therefore, in this study, we cloned and characterized the rainbo...

Primordial germ cells (PGCs) are the embryonic precursors of the gametes of the adult. PGCs derive from cells of the most proximal part of the cup-shaped epiblast corresponding to the presumptive region of the extraembryonic mesoderm. At 7.2 days post coitum (dpc) a small group of PGCs located at the base of the allantois can be recognised due to a strong alkaline phosphatase activity. Thus far...

Mouse primordial germ cells (PGCs) undergo sequential epigenetic changes and genome-wide DNA demethylation to reset the epigenome for totipotency. Here, we demonstrate that erasure of CpG methylation (5mC) in PGCs occurs via conversion to 5-hydroxymethylcytosine (5hmC), driven by high levels of TET1 and TET2. Global conversion to 5hmC initiates asynchronously among PGCs at embryonic day (E) 9.5...