Genetic manipulation technologies 1

Question 1

What is a Teratoma?

Answer 1

Tumours that form from germ cells that form oocytes and sperm

Can be benign or malignant

Question 2

What is pluripotency?

Answer 2

Ability of a cell to differentiate into many different distinct cell types

Embryonic stem cells are pluripotent

Question 3

How are Embryonic stem cells derived? (for sciencey stuff)

Answer 3

Derived from dissociating a blastocyst and culturing the Inner cell mass (ICM)

Question 4

You have a culture of Embryonic stem cells which you derived from the ICM of a blastocyst

How do you maintain their pluripotency?

Answer 4

Give them a swanky cocktail of cytokines and growth factors

The important ones are Leukaemia inhibitory factor (LIF) & BMP

Question 5

What 2 genes are markers of, and required for pluripotency?

Answer 5

Oct4

Nanog

Question 6

What does Oct4 do?

What happens if it’s missing?

Answer 6

Oct4 = transcription factor found in all ICM cells

Oct4-null embryos develop to Blastocyst stage but die because ICM cells are no pluripotent thus dont differentiate into anything

Question 7

What happens if an embryo has a dysfunctional Nanog?

Answer 7

Nanog-null ICM cells lose pluripotency and develop as extra-embryonic tissues (parietal endoderm)

Question 8

As mentioned previously - Leukaemia inhibiting factor (LIF) maintains an ESC’s pluripotency

What 3 pathways are involved in LIF’s action?

Answer 8

JAK-Stat3 pathway

MAP Kinase pathway (MAPK)

PI3 Kinase pathway

Question 9

What do LIF and BMP prevent an Embryonic stem cell from differentiating into?

Answer 9

LIF → Stops diff. into Mesoderm & Endoderm

BMP → Stops diff. into Neuroectoderm

Question 10

What happens if you withdraw LIF and BMP from cultures ESC?

Answer 10

They form ‘Embryoid bodies’

These have wee bits of endoderm, ectoderm, mesoderm in them

Question 11

fin

Answer 11

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