Lecture 3

Question 1

What does Gli-3 do?

Answer 1

Controls limb development of mice.
Loss of function = Xt extra toes phenotype
Gli acts as a repressor to regulate digit number.
Interacts with Hoxd11, hoxd12, hoxd13 which are negative regulators of digit number

Question 2

How would we go about analyzing the expression of the single gene?

Answer 2

RT-PCR (where when)
Live cell imaging (where when)
Promoter studies (where when why)

Question 3

What is live cell imaging and how does it work?

Answer 3

using a microscope to analyse gene activity and localisation
use a promoter within a gene, add a reporter gene e.g. lac Z - turns cells blue. can see where and when the cells are expressed.

Question 4

What is ChIP?

Answer 4

Chromatin Immunoprecipitation.

Used to identify the DNA binding sites of TFs.

Question 5

How do DNA microassays work?

Answer 5

Gene probes spotted on a microscope slife
Hybridised to labelled cDNA to show expression levels of each gene. Allows thousands of genes to be screened simultaneously.

Question 6

How can we test transcriptional networks?

Answer 6

Using ChIP, motif analysis and gene expression.