Primordial Germ Cell Development: Difference between revisions
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* '''Sall4 is Essential for Mouse Primordial Germ Cell Specification by Suppressing Somatic Cell Program Genes'''<ref name=PMID25263278><pubmed>25263278</pubmed></ref> "The Sall4 zinc finger protein is a critical transcription factor for pluripotency in embryonic stem cells (ESCs). ...Given that Sall4 and Prdm1 are known to associate with the histone deacetylase repressor complex, our findings suggest that Sall4 suppresses the somatic cell program possibly by recruiting the repressor complex in conjunction with Prdm1; therefore, it is essential for PGC specification." | |||
* '''Loss of Lhx1 activity impacts on the localization of primordial germ cells in the mouse'''<ref><pubmed>20845430</pubmed></ref> "To dissect the specific role of Lhx1 in germ cell development, we studied embryos with conditional inactivation of Lhx1 activity in epiblast derivatives, which, in contrast to completely null embryos, develop normally through gastrulation before manifesting a head truncation phenotype. Initially, PGCs are localized properly to the definitive endoderm of the posterior gut in the conditional mutant embryos, but they depart from the embryonic gut prematurely. The early exit of PGCs from the gut is accompanied by the failure to maintain a strong expression of Ifitm1 in the mesoderm enveloping the gut, which may mediate the repulsive activity that facilitates the retention of PGCs in the hindgut during early organogenesis. Lhx1 therefore may influence the localization of PGCs by modulating Ifitm1-mediated repulsive activity." | * '''Loss of Lhx1 activity impacts on the localization of primordial germ cells in the mouse'''<ref><pubmed>20845430</pubmed></ref> "To dissect the specific role of Lhx1 in germ cell development, we studied embryos with conditional inactivation of Lhx1 activity in epiblast derivatives, which, in contrast to completely null embryos, develop normally through gastrulation before manifesting a head truncation phenotype. Initially, PGCs are localized properly to the definitive endoderm of the posterior gut in the conditional mutant embryos, but they depart from the embryonic gut prematurely. The early exit of PGCs from the gut is accompanied by the failure to maintain a strong expression of Ifitm1 in the mesoderm enveloping the gut, which may mediate the repulsive activity that facilitates the retention of PGCs in the hindgut during early organogenesis. Lhx1 therefore may influence the localization of PGCs by modulating Ifitm1-mediated repulsive activity." | ||
* '''Dazl functions in maintenance of pluripotency and genetic and epigenetic programs of differentiation in mouse primordial germ cells in vivo and in vitro'''<ref><pubmed>19468308 </pubmed></ref> "We demonstrate that disruption of Dazl results in a post-migratory, pre-meiotic reduction in PGC number accompanied by aberrant expression of pluripotency genes and failure to erase and re-establish genomic imprints in isolated male and female PGCs, as well as subsequent defect in progression through meiosis. Moreover, the phenotypes observed in vivo were mirrored by those in vitro, with inability of isolated mutant PGCs to establish pluripotent EG (embryonic germ) cell lines and few residual Oct-4-expressing cells remaining after somatic differentiation of mESCs carrying a Dazl null mutation. Finally, we observed that even within undifferentiated mESCs, a nascent germ cell subpopulation exists that was effectively eliminated with ablation of Dazl." | * '''Dazl functions in maintenance of pluripotency and genetic and epigenetic programs of differentiation in mouse primordial germ cells in vivo and in vitro'''<ref><pubmed>19468308 </pubmed></ref> "We demonstrate that disruption of Dazl results in a post-migratory, pre-meiotic reduction in PGC number accompanied by aberrant expression of pluripotency genes and failure to erase and re-establish genomic imprints in isolated male and female PGCs, as well as subsequent defect in progression through meiosis. Moreover, the phenotypes observed in vivo were mirrored by those in vitro, with inability of isolated mutant PGCs to establish pluripotent EG (embryonic germ) cell lines and few residual Oct-4-expressing cells remaining after somatic differentiation of mESCs carrying a Dazl null mutation. Finally, we observed that even within undifferentiated mESCs, a nascent germ cell subpopulation exists that was effectively eliminated with ablation of Dazl." | ||
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* '''Prdm1 and Prdm14''' - PR domain proteins expressed in mouse (E6.25), suppresses somatic differentiation. | * '''Prdm1 and Prdm14''' - PR domain proteins expressed in mouse (E6.25), suppresses somatic differentiation. | ||
* '''Sall4''' - zinc finger protein, inactivation of this transcription factor in mouse can reduce PGC number.<ref><pubmed>25263278</pubmed></ref> | * '''Sall4''' - zinc finger protein, inactivation of this transcription factor in mouse can reduce PGC number.<ref name=PMID25263278><pubmed>25263278</pubmed></ref> | ||
A study has recently identified 11 genes that are specifically expressed in male and female fetal germ cells, both in vivo and in vitro, but are not expressed in embryonic stem cells.<ref><pubmed>20940145</pubmed></ref> | A study has recently identified 11 genes that are specifically expressed in male and female fetal germ cells, both in vivo and in vitro, but are not expressed in embryonic stem cells.<ref><pubmed>20940145</pubmed></ref> |
Revision as of 08:00, 12 October 2014
Embryology - 30 May 2024 Expand to Translate |
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Introduction
Early in development at the time of gastrulation a small group of cells are "put aside" to later form oocytes and spermatozoa. This population of cells is described as the primordial germ cells (PGCs). These cells also migrate initially into the posterior endoderm that forms the hindgut and from there into the genital ridge that will be the site of the developing gonad. The maintenance of pluripotency within this cell population may arise through epigenetic modifications that suppress somatic differentiation programs.
This population of cells when transformed is also thought to give rise to testicular germ cell tumours.
Some Recent Findings
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More recent papers |
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This table allows an automated computer search of the external PubMed database using the listed "Search term" text link.
More? References | Discussion Page | Journal Searches | 2019 References | 2020 References Search term: Primordial Germ Cell <pubmed limit=5>Primordial Germ Cell</pubmed> |
Textbooks
- Human Embryology (2nd ed.) Larson Chapter 10 p261-306
- The Developing Human: Clinically Oriented Embryology (6th ed.) Moore and Persaud Chapter 13 p303-346
- Before We Are Born (5th ed.) Moore and Persaud Chapter 14 p289-326
- Essentials of Human Embryology, Larson Chapter 10 p173-205
- Human Embryology, Fitzgerald and Fitzgerald Chapter 21-22 p134-152
- Developmental Biology (6th ed.) Gilbert Chapter 14 Intermediate Mesoderm
Primordial Germ Cell Migration
Species Comparison of Migration
Stages of primordial germ cell migration[7]
Mouse Migration Movies
The movies below show labeled primordial germ cells (green) migrating within the mouse embryo between the periods of E9.0 to E10.5 into the genital ridge region that will later form the gonad.
Mouse Primordial Germ Cell Migration | |||||||||||
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- Links: Mouse Development
Cell Structure
The images below are scanning electron micrographs of the surface of a chicken primordial germ cell that has been grown in culture.[8]
The first image shows the whole cell and the second image shows detail of the cell surface showing extensions.
DNA Methylation
Mouse primordial germ cell DNA methylation[9]
Demethylation
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X-linked Gene Expression
Mouse- X-linked gene expression during primordial germ cell development.[10]
Each circle graph indicates the ratio of cells that are positive (yellow) and negative (black) for each gene, and biallelically (red) and monoallelically (blue) expressed in cells positive for each gene.
- Links: X Inactivation | Mouse Development
Molecular
- Prdm1 and Prdm14 - PR domain proteins expressed in mouse (E6.25), suppresses somatic differentiation.
- Sall4 - zinc finger protein, inactivation of this transcription factor in mouse can reduce PGC number.[3]
A study has recently identified 11 genes that are specifically expressed in male and female fetal germ cells, both in vivo and in vitro, but are not expressed in embryonic stem cells.[12]
PGC Markers: alkaline phosphatase-positive, Oct4 (POU5F1), Fragilis (IFITM1)[13], Stella (DPPA3), Dazl, and Vasa (DDX4).
- Steel factor - (KITLG) a ligand for the KIT tyrosine kinase receptor.
- DAZL
- dead end - coding an RNA binding protein mainly expressed in the germ cells of vertebrates.
- Blimp1 - B-Lymphocyte induced maturation protein-1 (PRDM1)
- Prmt5 - protein arginine methyltransferase-5
- Nanog - knockdown induces apoptotic cell death in mouse migrating primordial germ cells.[14]
- AID - Activation-Induced cytidine Deaminase enzyme required for demethylation (removal of CpG methylation). Within the genome, DNA methylation is associated with epigenetic mechanisms and occurs at cytosine residues that are followed by guanines.[15]
Abnormalities
Teratomas
Common group of fetal tumors occuring along the body midline, anywhere from the coccyx to the pineal gland, reflecting the developmental PGC migration pathway (for review see [16]).
- Histologically classified as either mature or immature.
- Immature elements consisting principally of primitive neuroglial tissue and neuroepithelial rosettes and have have a generally favorable prognosis.
- Sacrococcygeal teratomas - most common site (70%–80% of all teratomas).
- classified into four types based on the amount of mass present externally versus internally.
Testicular germ cell tumours (seminoma)
References
- ↑ <pubmed>20886037</pubmed>| PLoS One.
- ↑ <pubmed>19997484</pubmed>| PMC2777314 | PLoS Genet.
- ↑ 3.0 3.1 <pubmed>25263278</pubmed>
- ↑ <pubmed>20845430</pubmed>
- ↑ <pubmed>19468308 </pubmed>
- ↑ <pubmed>19279135</pubmed>
- ↑ <pubmed> 20027186</pubmed>| Nature Reviews Molecular Cell Biology
- ↑ <pubmed>20886037</pubmed>| PLoS One.
- ↑ <pubmed>21886830</pubmed>| PLoS One.
- ↑ <pubmed>17676999</pubmed>| PMC1950944 | PLoS Genet.
- ↑ <pubmed>19468308</pubmed>| PLoS One.
- ↑ <pubmed>20940145</pubmed>
- ↑ <pubmed>12659663</pubmed>
- ↑ <pubmed>19906868</pubmed>
- ↑ <pubmed>20236475</pubmed>
- ↑ <pubmed>15653597</pubmed>
Reviews
<pubmed>20371640</pubmed>| Reproduction <pubmed>20027186</pubmed> <pubmed>19875497</pubmed> <pubmed>19442193</pubmed> <pubmed>17446386</pubmed> <pubmed>15666347</pubmed> <pubmed>11565804</pubmed> <pubmed>11061420</pubmed>
Articles
<pubmed>19578360</pubmed> <pubmed>18953407</pubmed>
Search PubMed
Search Pubmed: Primordial Germ Cell Migration | Primordial Germ Cell | Testicular germ cell tumours
External Links
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Glossary Links
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Cite this page: Hill, M.A. (2024, May 30) Embryology Primordial Germ Cell Development. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Primordial_Germ_Cell_Development
- © Dr Mark Hill 2024, UNSW Embryology ISBN: 978 0 7334 2609 4 - UNSW CRICOS Provider Code No. 00098G