From genes to cells to cell behaviours

Question 1

What is emergent behaviour?

Answer 1

The organisation of cells at one level, interacting with each other in an environment to form more complex behaviours as a collective

Question 2

What is the function of a cell reflected in?

Answer 2

The shape of the cell

Question 3

How do chromosomes, which are identical in each cell direct cell differences?

Answer 3

Differential gene activity causing the restriction of potency

Question 4

How can gene expression in different cells be altered?

Answer 4

Autonomously/cell intrinsically

Non-autonomously/cell extrinsically

Question 5

What is autonomous/cell intrinsic control?

Answer 5

The cell controls itself

Question 6

What is non-autonomous/cell extrinsic control?

Answer 6

Factors from other cells control the cell in question

Question 7

How does development occur?

Answer 7

It is progressive, cells gradually become committed to their fates by restricting their potency

Question 8

What is a ‘ restriction in potency’ and when does it occur?

Answer 8

The cell is capable of differentiating into fewer cell types - occurs when the cell becomes committed to its fate

Question 9

What is ‘cell fate’?

Answer 9

The final cell type that a developing cell will become, as it goes through development and restricts its potency

Question 10

What does differential gene expression produced?

Answer 10

Change in gene transcription

Question 11

How is mammalian differentiation achieved?

Answer 11

Systematic, sequential changes in gene expression, brought about through interactions between the NUCLEUS and CHANGING CYTOPLASMIC ENVIRONMENT

Question 12

What determines if the cell is going to change transcriptional profile?

Answer 12

Signalling between the nucleus and the cytoplasmic environment of the cell

Question 13

How can gene expression be regulated?

Answer 13

• Chromatin modification
• Transcription
• Transport to cytoplasm
• Translation
• Degradation of mRNA
• Protein processing
• Degradation of protein
• Transport to cellular destination

DIFFERENTIAL REGULATION AT THE LEVEL OF GENE ENHANCERS AND GENE PROMOTERS

Question 14

What are enhancers?

Answer 14

Part of the DNA sequence which sit upstream or downstream of the coding sequence and can increase or decrease transcription of a gene

Question 15

What binds to enhancers in DNA? Causing what to happen?

Answer 15

Activator proteins to help to activate transcription by opening up the genome and allow transcription machinery to access it

Repressor proteins (silencers) bind to repress transcription

Transcription factors bind

Question 16

What are promoters?

Answer 16

Part of the DNA sequence which sit upstream of the coding sequence, near the transcription start site, indicate where transcription of DNA by RNApol occurs

RNApol binds here

Question 17

How do transcription factors usually act?

Answer 17

In a complex with many other proteins (cotranscription factors/ coregulatory elements)

Question 18

What acts together to control the expression of a single gene?

What do we focus on in BMS249?

Answer 18

Many enhancer elements and numerous transcription factors

Focus on the individual TF which is the dominant TF which determines if a gene is expressed

Question 19

What determines if a particular transcription factor is expressed in a cell? (2 ways)

Answer 19

1) TF in cell 1 regulated by a signal from cell 2 (Eg. morphogens) (non-autonomously)
2) TF in cell one can be regulated by an earlier-expressed TF in the same cell (autonomous)

Question 20

What do the proteins of a cell determine?

Answer 20

• Behaviours of the cell (proliferation, migration)
• What circuits will occur, as proteins interact with each other (protein organisation)
• What the cell will look like (shape, type)
• What function the cell will have (receptor compliments, neurotransmitters made)
• Direct emergence of the cell

Question 21

What builds the structure of the brain, CNS, PNS, behaviour and mind?

Answer 21

Proteins and their network assembly and function

Question 22

What is differentiation?

Answer 22

Process at which cells become different from each other and acquire specific properties

Question 23

What is differentiation governed by?

Answer 23

Changes in gene expression which dictate the repertoire of protein synthesised