Embryonic germ and stem cells Flashcards
What are gonadal stem cells?
Specialised cells set aside in a undifferentiated state for the next generation
What is a ‘P. lineage cell’?
Specialised cells in the C.Elegans which contain p granules- bind to DNA and block transcription, block translation in the cytoplasm
What are the characteristics of all vertebrate germ cells in their earliest stages?
- No transcription
- No translation
- No differentiation
- They undergo meiosis
Where are PGCs formed?
Outside the embryo
Posterior end of extra-embryonic epiblast (at the junction with the hypoblast)
What are PGCs protected from?
Signals in the embryo that are specifying the axes and orchestrating differentiation
What does convergent extension in vertebrates cause?
The primitive gut to form-> PGCs migrate to the posterior part of the developing gut-> then migrate to the gonads
What do germ cells do in drosophila?
Passively ride the endoderm
Driven to the gonad with gonad precursor cells
Where do the germ cells attach in the ovaries of the drosophila?
The stromal cap
Where do the germ cells attach in the testes of the drosophila?
The hub cells
What is formed if PGCS fail to migrate?
Teratoma
What are ‘support cells’?
Cells in mice which travel with PGCs- maintain their stem cell phenotype- secrete stem cell factor SCF
What do PGCs follow in mice?
A fibronectin trail
Chemoattractant- Sdf-1
What are the epigenetic silencing mechanisms?
DNA methylation
Histone acetylation
