functional genomics 1 – where is my gene expressed? Flashcards
Gene expression can be analysed at two levels
RNA and protein.
The process of analysing gene expression looks at both…
… RNA expression and protein expression
Just as DNA molecules can be separated by gel electrophoresis so can …
… RNA molecules
What happens to RNA when run on a gel?
RNA is heated to denature secondary structure and runs towards the positive terminal as its sugar phosphate backbone is negatively charged
What is used for rna gels?
Total RNA is usually used and includes rRNA (present as bands) as well as mRNA (present as a smear)
What is northern blotting?
In Northern Blotting RNA is transferred to a nylon or nitrocellulose membrane.
Why isnt rna denatured in alkali first in northern blotting?
1 – they are single stranded anyway and 2 – they would degrade!
What is RNA hybridised with in northern blotting?
hybridised with a dna prob
what is temporal regulation?
a type of regulation of gene expression in which a gene is only expressed at a specific time in development; for example, genes that are only expressed in the light or during flower development.
what does northern blotting answer?
This answers the ‘where, when, why’ questions of gene expression
the questions need to be answered because gene expression is regulated:
what doesnt northern blotting tell us?
often doesn’t say in which cells within any particular tissues a gene is expressed (note it did with the astrocytes but these were in culture – is this a realistic model of what happens in the human brain?
