Lecture 17. Cell Signalling in Development Flashcards

1
Q

What is induction ?

A

Where one group of cells influences the development of a neighbouring group of cells

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

Who was induction first demonstrated by ?

A

Hans Spermann and Hilde Mangold

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

What is the important conclusion of the organiser experiment ?

A

Organiser cells from the donor could change the fate of the recipient cells and can set in motion a chain of events leading to the production of a new body plan

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

How can induction be achieved at the molecular level ?

A

By cells sending molecular signals to neighboring cells

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

What type of cell signaling is used to achieve induction at molecular level ?

A

Paracrine signalling

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

What is signal transduction ?

A

The mechanism that relays the signal received at the cell surface to the nucleus

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

What is the ultimate effect of cell signaling at the cell surface ?

A

A change in gene expression in the nucleus

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

What do cells need on their cell surfaces to respond in a particular way ?

A

A particular receptor

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

What happens as a result of only cells that possess a particular receptor on their surface can respond in a particular way ?

A
  1. Some cells will not respond at all to a signal if they dont have a receptor
  2. Two different cells can respond in different ways to the same signal (if they possess different receptors)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is competence ?

A

The ability to respond to a signal

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

What is the ligand or signal of the TGF-beta pathway ?

A

BMP2

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

What is the receptors of the TGF-beta pathway ?

A

Tgfbr1

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

What is the transcription factor of the TGF-beta pathway ?

A

Smad

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

What are the roles in development in TGF-beta pathway ?

A
  1. Roles at all stages

2. Mesoderm induction

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

What is the signal in the Wnt signalling pathway ?

A

Wnt1

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

What is the receptor in the Wnt pathway ?

A

Frizzled/ B-catenin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the transcription factor in the Wnt signaling pathway ?

A

Tcf/Lef

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is some of the roles in the development of the Wnt pathway ?

A
  1. Roles at all stages
  2. Positional information at all regions
  3. Limb development
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the signal in the Delta-notch pathway ?

A

Delta-like

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is the receptor in the delta-notch pathway ?

A

Notch

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is the transcription factor in the delta-notch pathway ?

A

Cst

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What are the roles in development in the delta-notch pathway ?

A
  1. Roles at all stages
  2. Left-right asymmetry
  3. Neurogenesis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is the signal in the Hedgehog signaling pathway ?

A

Sonic hedgehog

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is the receptor in the hedgehog pathway ?

A

Patched/smoothened

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is the transcription factor in the hedgehog pathway ?

A

Gli

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What is the role in development in the hedgehog signaling pathway ?

A
  1. Positional information - neural tube and limb
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is the signal in the FGF pathway ?

A

FGF8

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What is the receptor in the FGF pathway ?

A

Fgfr

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What is the transcription factor in the FGF pathway ?

A

Not known

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What are the roles in FGF pathway ?

A
  1. Roles at all stages
  2. AER of limb bud
  3. Gastrulation - maintaining mesoderm
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What is the signal in the Hippo pathway ?

A

Stress

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What is the receptor in the hippo pathway ?

A

Fat4 eg yap/taz

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What is the transcription factor in the hippo pathway ?

A

Tead4

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What is the roles of hippo in development ?

A
  1. Early mammalian

2. Kidney/skeletal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Induction in the C. elegans: What does the vulva develop from ?

A

Six cells present on the ventral surface of the second stage larva

36
Q

Induction in the C. Elegans: What initiates a cascade of signals that establishes the fate of the precursor cells ?

A

A single cell in the embryonic gonad, called the anchor cell

37
Q

What is the signaling pathway involved in the C. Elegans ?

A

EGF pathway

38
Q

What is the function of hedgehog ?

A

Definition of segments

39
Q

Where was the hedgehog gene first identified ?

A

In drosphilia mutant screens

40
Q

What is the ventral surface of the hedgehog gene covered in ?

A

Denticles

41
Q

How many homologues does the vertebrate of drosphilia hedgehog have ?

A

3

42
Q

What are the 3 homologues of drosphilia hedgehog ?

A
  1. Ihh - Indian hedgehog
  2. Dhh - desert hedgehog
  3. Shh - sonic hedgehog
43
Q

Where is hedgehog expressed ?

A

Restricted domains

44
Q

What maintains the segment boundary in hedgehog ?

A

Interactions between hedgehog and wingless

45
Q

What is the role of Ihh in gene expression in mouse embryo ?

A

In bone formation

46
Q

What is the role of Shh in gene expression in mice ?

A

neural tubes developing limb buds

47
Q

What is the role of Dhh in gene expression in mouse embryo ?

A

Male reproductive system - testes development

48
Q

Where is the zone of polarising activity located ?

A

In the posterior mesoderm

49
Q

What is the zone of polarising activity defined by ?

A

Its activity when transplanted to another region

50
Q

What happens to the zone of polarising activity when transplanted to the anterior ?

A

It induces a duplication of the A/PP pattern of digits that will form

51
Q

What was used to show where Shh is expressed ?

A

In situ hybridisation

52
Q

What is the zone of polarising activity molecularly defined by ?

A

Sonic hedgehog gene expression

53
Q

What does transplanting cells that express sonic hedgehog to the anterior limb mimick ?

A

zone of polarising activity transplantation

54
Q

What is the sonic hedgehog a major active component of ?

A

Zone of polarising activity

55
Q

What is sonic hedgehog required for ?

A

Pattern formation of the limb along the anterior posterior axis

56
Q

What are mutations in the sonic hedgehog responsible for ?

A

Human limb malformations such as human preaxial polydactyl

57
Q

What does the removal of the sonic hedgehog gene expression in the developing mouse limb lead to ?

A

Truncation of the distal structure

58
Q

What does the removal of the AER at different stages lead to ?

A

Truncation of the limb at different points along the p/d axis

59
Q

Where is AER a major signalling centre of ?

A

Limb

60
Q

What does AER secrete ?

A

FGFR

61
Q

What happens if AER is removed but beads containing FGF8 are added ?

A

Limb development can continue near to normal

62
Q

What is FGF8 expression in AER necessary for ?

A

The outgrowth of the limb and for the patterning of the limb along the proximal/distal axid

63
Q

What is the function of wingless ?

A

Works with hedgehog to establish segment boundaries

64
Q

Where is wingless expressed ?

A

Restricted domains

65
Q

In mice and humans how many wnt genes are there ?

A

19

66
Q

What are wnt proteins critical for in mice and humans ?

A
  1. Patterning somites

2. Development of nervous and muscle systems

67
Q

What does Wnt bind do ?

A

The frizzled receptor

68
Q

How many frizzled receptors in mice ?

A

10

69
Q

What is the roles of development in the wnt signalling in mice ?

A
  1. Patterning of cells
  2. Regulating cell proliferation
  3. Patterning of limbs
  4. Urogenital system development
  5. Stem cell control
70
Q

What are the series of events that cells are given instructions on how to behave ?

A
  1. when to divide
  2. when to migrate
  3. when to invade
71
Q

What sort of disease in cancer ?

A

Progressive

72
Q

What type of growth occurs in cancer ?

A

Growth control loss

73
Q

What type of localised growth occurs in cancer ?

A

Benign

74
Q

What does benign localised growth in cancer result in ?

A

Metastasis and malignancy

75
Q

What are some environmental conditions that cause mutations in genes that can cause cancer ?

A
  1. UV irradiation
  2. Cigarette smoke
  3. Certain viruses
  4. High dietary fat
76
Q

What are the two categories of genes that when mutated can lead to cancer ?

A
  1. Proto-oncogenes

2. Tumour suppressors

77
Q

What are proto-oncogenes and tumour supressors function ?

A

Regulators of cellular behavior

78
Q

What is a common cause of colon cancer ?

A

Wnt and cancer pathway malfunction

79
Q

What is the function of wnt genes in the gut ?

A

Needed for development and regulation of stem cell population for repair of gut lining

80
Q

What is the function of the gene product APC ?

A

Involved in controlling how a wnt signal is interpretated inside a receiving cell

81
Q

What can stem cells in the adult gut be stimulated to do ?

A

To divide and produce more gut lining cells by the wnt cell signalling molecule

82
Q

What does APC help to do ?

A

Keep the wnt pathway off in the absence of wnt signalling

83
Q

By studying embyronic development what can we find out ?

A
  1. How cell controls are established in normal cells
  2. How events such as cell division, migration and invasion are controlled in the embryo
  3. How programmed cell death is controlled in the embryo
  4. How a blood supply is established to nourish developing organs
84
Q

What is a possible treatment for cancer ?

A

If the Shh pathway is blocked the tumor regresses

85
Q

What is tumorigenesis ?

A

Sporadic mutations or other mechanisms

86
Q

What is hedgehog involved in cancer ?

A

Evidence for re-activation of the pathways in tumorigenesis