Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Animal biotechnology > Mammalian Embryo Development > Flashcards

Mammalian Embryo Development Flashcards

1
Q

What is the cavity inside the blastocyst (32-64 cells) called?

A

Blastocoel

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Before implantation of the embryo into the uterine wall, what does it need to do first?

A

It needs to undergo ‘hatching’ from the zona pellucid (provides protection + support) so it can implant more easily.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

After fertilisation, when is methylation at its lowest?

A

When the blastocyst has formed.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the two ways in which gene expression can be controlled?

A
  1. DNA methylation
  2. Histone modifications
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is expressed to suppress Xist on the active chromosome?

A

Tsix

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Explain the stages of X chromosome inactivation within the developing embryo

A
  1. Cells within the morula undergo random X inactivation
  2. Within the blastocyst, the ICM undergoes reactivation of X chromosomes to ensure that all cells have the ability to form any cell within with body
  3. Random XCI occurs for those cells going to form the specific tissues
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Where does Hippo signalling occur and how does it work?

A

Inner cells to form the ICM. YAP1 is phosphorylated to cause cytoplasmic retention and protein degradation. It does not enter the nucleus.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Which cells have Hippo signalling off?

A

Outer cells. YAP1 is not phosphorylated and so it enters the nucleus to enable Cdx2 expression. These now form the trophectoderm.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Where are the TFs Nanog and GATA6 expressed and what do they give rise to each?

A

ICM
Nanog = Epiblast (future primitive ectoderm)
GATA6 = Primitive endoderm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the use of Embryonic Carcinoma Cells (ECC) from teratocarcinomas?

A

These pluripotent stem cells can be injected into a blastocyst to form a chimeric animal.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What two components are needed to support cancer cell culture?

A

Basal medium & Foetal bovine serum (contains lots of nutrients and growth factors)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What other component is needed as well for mESCs culture?

A

Feeder cells (can be embryonic fibroblast cells)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Which two kinases need to be inhibited when culturing mESCs and why?

A
  1. p-ERK
  2. GSK3

They both are going against pluripotency and promote cell differentiation. GSK3 phosphorylates b-catenin in the Wnt pathway, making it a target for the destruction complex. B-catenin is needed for cell pluripotency.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

The cell culture will now have basal medium + LIF + p-ERK & GSK3 inhibitor

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Which specific stem cells represent the naive and primed pluripotency state in mice?

A

Naive = ESCs
Primed = EpiSCs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the difference between naive and primed state?

A

Naive cells are in an undifferentiated and ‘ground’ state from the ICM. Primed pluripotency are cells which represent a more lineage-restricted state and devlopmental potential (pre implantation). They are post implantation state.

17
Q

Which pathways maintain the primed state?

A

Tfgb & FGF pathways.

18
Q

It is unknown whether hESCs have a ground state as we cannot test this. We also cannot test if the hESC have the ability to form blastocyst chimeras.

A
19
Q

hESC/EpiSC have a bias towards their differentiation that is why they are primed and not naive.

A
20
Q

What is required for self-renewal of ground (naive) state rodent (mice) ESCs?

A

LIF/STAT3

21
Q

What is required for self-renewal of primed state EpiSCs/hESCs?

A

FGF/Erk. These cause differentiation in ground state ESCs.

22
Q

What is the X chromosome status of ground (naive) state and primed state stem cells (ESC/EpiSC)?

A

Both X chromosomes are active in ground state but one of the X chromosomes is inactive in the primed state.

23
Q

Primed state occurs post-implantation, what day is this in mice?

A

Between E6.5-E7.0

24
Q

In humans, the state between naive and primed is called the formative phase which is day 8 - day 12.

A
25
Q

Why is the formative phase important?

A

E5.5 in mice - Because it is the first time the cells can respond to signalling despite being in a naive state prior, but they need to be in the formative phase to be induced.

26
Q

What are the three signalling molecules for self-renewal in EpiSC or hESC?

A

Wnt, FGF, Wnt

27
Q

How can you maintain FS (Formative Stem cells) in culture then?

A
  1. Remove Wnt
  2. Remove FGF
  3. Minimise Activin
  4. Remove RA
28
Q

The motivation to make FS Cells is because they are unbiased and can then hopefully produce desired organs etc for individuals. Naive cells do not respond to differentiation signals like the FS Cells do (post-implantation).

A
29
Q

The transition of Naive to Formative is Capacitation

A
30
Q

What is zygote genome activation?

A

When the embryonic genome becomes transcriptionally active rather than relying on RNAs and proteins in the egg.

31
Q

At which stages in mice and humans respectively does zygote genome activation occur?

A

Mouse = Day 1.25 (2-8 Cells)
Humans = Day 4

32
Q

In attempts to produce naive hESCs, which genes can be overexpressed?

A

Nanog & Klf2
t2iL & Go

33
Q

Insert Nanog & Klf2 transgenes into the hESCs, and introduce t2iL+Go (aPKC inhibitor). The PKC inhibitor is a GSK inhibitor. Cells start to express Klf4, TFCP2L1, and STELLA - known mouse naive regulators = naive state

A
34
Q

What are the naive hESC culture conditions and why for each component?

A

PD03 = FGF inhibitor + prevents formative epiblast state
XAV939 = Trophectoderm inhibitor
Go = Trophectoderm inhibitor
LIF = Cell proliferation

35
Q

What is a main difference between naive mESC and naive hESC?

A

hESCs can produce the trophectoderm and mESCs cannot.

36
Q

What are the three types of stem cells derived from the early embryo?

A
  1. Embryonic Stem Cells (pre-epiblast)
  2. Extraembryonic Endoderm Cells
  3. Trophoblast Stem Cells
37
Q

What is a blastoid?

A

A blastoid refers to a structure resembling a blastocyst but created artificially in the laboratory.

38
Q

Why is it useful that naive hESCs produce the trophectoderm also?

A

No need to mix naive hESCs with trophoblast stem cells.

39
Q

What does GATA4 resemble?

A

Hypoblast/primitive endoderm/extraembryonic layers

Animal biotechnology (8 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions