Brainscape's Knowledge GenomeTM

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


See full index

Cells To Organisms > Differentiation > Flashcards

Differentiation Flashcards

1
Q

Definition of differentiation

A

unspecialized cells becoming specific during embryo development AND tissue homeostasis

tissue homeostasis = throughout life

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

Housekeeping proteins vs specialised proteins

A

housekeeping= non-cell-type specific (ie actin)
Specialised = cell-type specific (ie antibody chain, only in immune cells)

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

Cell fate determination

A

cells fate becoming progressively defined

driven by interplay between cell lineage and cell environment

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

Cell lineages

A

being able to trace a cell back where it came from

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

Lineage restriction

A

ability to differentiate

eg blastocysts to blood cells

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

Developmental potency

A

at different stages, cells have different potential to give rise to different cell types

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What do blastocysts differentiate into?

A
  1. Ectoderm
  2. Mesoderm
  3. Endoderm
    as well as germ cells and trophectoderm->placenta
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What does the ectoderm differentiate into?

A
  1. Skin -> hair, sweat glands
  2. CNS -> neurons, glila, retina (photoreceptors and pigment cells)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What does mesoderm differentiate into?

A
  1. Bone
  2. Muscle-> smooth, cardiac, skeletal
  3. Kidney
  4. connective tissue
  5. adipose tissue
  6. Vessels
  7. Blood stem cells-> Erythrocytes, Macrophages, lymphocytes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What does the endoderm differentiate into?

A
  1. Liver
  2. Gut
  3. Lungs
  4. Pancreas-> exocrine and endocrine
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What does the endoderm differentiate into?

A
  1. Liver
  2. Gut
  3. Lungs
  4. Pancreas-> exocrine and endocrine
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Haematopoeisis

A

All germ cells shared one common ancestor, example of cell fate determination (ie CLP to NK cells)

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

What experiements support gene constancy?

A
  1. Frog embryo nucleus implanted into adult skin cell results in cloned tadpole
  2. If apply myosin TF in a red blood cell it starts forming muscle fibres
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Where and when is transcription regulated?

A

Where: at a start site (ie TATA, RNA polymerase is guided to start site by helper proteins)
When: whenever a TF binds to the enchancer region

TF is found in the nucelus and sometimes in the cytoplasm

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

What does control gene expression do?

A

Determines differentiation which determines protein content which determines morphology and function which determines behavior during development

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

How does an activator TF regulate transcription?

A

Binds to enhancer domain and turns gene expression on

17
Q

How does a repressor TF regulate transcription?

A

Binds to enhancer domain and turns gene expression off

18
Q

How do TF recruit RNA polymerase?

A
  1. Histone aceytl transferase (loosens the histones to make genes more accessible)
  2. Chromatin remodelling complex (promote RNA polymerase binding by straightening out section of chromosome to make DNA more accessible)
19
Q

Do TF regulate multiple target genes?

A

They can. For example: E-Box is found in myosin II, troponin, tropomysoin, creatine phosphate kinase, so they are all target genes bc all have E-box which is turned on by MyoD

20
Q

What steps are in muscle cell differentiation?

A
  1. Proliferation (dividing myoblasts)
  2. Cell cycle exit (cells align)
  3. Terminal differentiation (specific proteins arise resulting in working muscle fibre
21
Q

What does MyoD do? What experiments proved this?

A

Binds to E-box promoter region on genes needed for muscle cell differentiation
Loss-of- function experiement: Knockout MyoD then myoblasts never differentiate, stalled after cell cycle exit.
Gain of function experiement: transfect a plasmid with expressed MyoD and they turn into muscles

22
Q

What does Glabra1 do?

A

TF for plant leaf trichomes. No Glabra1=no trichomes

23
Q

What does GATA1 do?

A

TF for erythrocytes. No GATA1= no RBC, differentiation at proerythroblast.

RBC= red blood cells

24
Q

What is a homeodomain?

A

example of a DNA binding domain. 5’-ATTA-3’. TF is pushed into the major groove of DNA by two other helices so residues from the TF interact with base pairs. Pattern of H-bonding dictates whether TF activates anything?

25
Q

What are some transcription factor families?

A

bHLH, Homeodomain, Myb, Zinc-finger, MADS box

bHLH and homeodomain and zinc finger is present in all organisms, Myb only in arabodopsis, MADS box only in arabodopsis and humans

26
Q

What affect does phosphorylation have on TF?

A

Phosphorylation is a commong post translational modification. It may activate or inhibit the TF. Eg GF actiavte MAP kinase that phosphorylates TF and activates gene expression Eg2. EGF binds its receptors and MYC phosphorylated and becomes stable and activates transcription of cyclins

27
Q

What are the three bHLH TF involved in guard cell differentiation?

A

SPCH-> Mute-> FAMA
No SPCH= no cell fate determination after progenitor
No Mute= no cell fate determination after meristemoid
No FAMA= no cell differenentiation into guard cells

28
Q

What bHLH TF are involved in muscle cell differentiation? Any other signals involved?

A

bHLH: MyoD, Myf5, Mrf4, Myogenin
Homeodomain: Pax3
Regulatory signals= GF, WNT, SHH, BMP

29
Q

What is the muscle gene regulatory network? (GRN)

A

SHH activates Myf4 which activates Myf5 (determination) and MyoD. Pax3 activates MyoD and Myf5 as well, MyoD and Myf5 both activate themselves. Both activate myogenin, GF inhibits this. Myogenin leads to muscle specific proteins production

Myf5 present means the signal is received, and Pax3 means its correct lineage. Both these need too be present to turn MyoD on.

30
Q

What targets MyoD for degradation?

A

CDK phosphorylate MyoD and Myf5 which target it for proteolytic degradation

31
Q

What is the effect of master regulator PAX6 mutation?

A

The whole eye is gone in drosphilia, this is bc PAX6 encodes a paired box and homeodomain TF. PAX6 needed for multiple different cell types. Expressing PAX6 in the leg or wing results in eyes forming there. PAX6 is highly conserved (as master regulators usually are) and specifies eye promordium in jellyfish and worms too

32
Q

What is Waddingtons landscape?

A

Ball rolling down the hill with vallies and such, represents binary cell fate choices a cell makes
Eg Pu.1 and GATA1 compete for different pathways. Pu.1 antagonizes GATA1 and binds to it after GATA1 binds DNA and knocks off the coactivator protein and induces methylation

33
Q

Why is Waddingtons theory not the best? What two factors determine cell fate decisions?

A

Cell fate descions are determined by cell lineage (what choices is available) and environment (what choice is appropriate)
Cdx2 expression gives gut cells competence (cell lineage) and if FGF2 received then Cdx2 activates Pdx1 (environment)

Cells To Organisms (8 decks)

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