Lecture 2 - Early development and Pluripotent Stem cells Flashcards
What are pluripotent stem cells
capacity to self-renew by dividing and to develop into the three primary germ cell layers of the early embryo and therefore into all cells of the adult body, but not extra-embryonic tissues such as the placenta
Where does fertilisation occur
infundibulum, within oviduct
What is the name of the sections of the fallopian tube
From closest to the uterus to the fimbriae
Isthmus, ampulla, infundibulum
are ectoderm, mesoderm, endoderm pluripotent
yes
Where will morula be located?
isthmus
Where does 2-cell stage and zola pellucida occur
Ampulla
Where is blastocyst located
Blastocyst
At which day does embryo develop into early blastocyst?
day 3.5
At which day does embryo develops into late blastocyst
Day 4.5
What are the ways to test for pluripotent stem cells (in vitro)?
Differentiation, teratoma formation, germline chimerism, tetraploid complementation,
Which pluripotency test is the least stringent
Differentiation
What is differentiation
Differentiate spontaneously
in vitro into derivatives of the
three germ layers:
ectoderm, mesoderm, endoderm – pluripotent
What variables are there for differentiation test?
• The expression for differentiation
markers is not a test for functionality:
Any changes in culture conditions can
stress the cells or induce differentiation
Does differentiation test functionality?
No
What is teratoma formation
Formation of teratomas when injected into immune-deficient mice
• Differentiate spontaneously in vivo into derivatives of the
three germ layers: ectoderm, mesoderm, endoderm due to loss of
pluripotency and exposure to signals in the new environment that
induce differentiation
What teratoma formation cannot test
Do not test for the ability to promote normal development
What is germline chimerism?
ES cells from another animal is injected into one animal’s donor blastocyst. Resulting the ES cells contributing to all tissues of the resulting offspring
What can germline chimerism test?
germline competency
What does germline chimerism not test?
Does not test for complete pluripotency
i.e problems caused by epigenetic defects
affecting development
What is tetraploid complementation?
Tetraploid complementation
produced by injecting ES cells into a tetraploid (4n) blastocyst
because 4n host cells cannot contribute to somatic lineages, embryo is exclusively composed of the cells formed from the test cells
Which test is the most stringent for pluripotency?
Tetraploid complementation
What can tetraploid complementation test?
germline competency
How many cell type does an early blastocyst have?
2, trophoblast and inner cell nass
How many cell type does a late blastocyst have?
3, trophoblast and epiblast and hypoblast
