copy number of gene in genome - (Feb/21/2011 )
can someone tell me if i understand the significance of copy number in the genome correctly? this is what i have written down:
how i understand it is that copy number of a gene is basically how many copies of a gene there are in the genome. so there could be one copy of a particular gene in the genome, or several copies of a particular gene in a genome in its natural state.
copy number can be linked to diseases when the number of copies of a particular gene in its natural state increases or decreases. this is called copy number variation and has been investigated in many studies.
so if the number of copies of a gene increases or decreases, is that the same way of saying the gene is being over or under-expresssed in the genome? for example, take a cancer cell. due to the complexity of a cancer cell, a particular gene can be over or underexpresssed, so this means the number of copies of the gene are also lower or higher.
The number of a particular gene present per genome does not change due to expression level -- expression level changes influence the number of RNA transcripts produced from the gene and, ultimately, how much of that gene's product (protein) is produced, but not the number of copies of the gene itself.
So, while expression level does not change the gene's copy number, the copy number of a gene in a genome can influence the expression level -- if you have two copies of a particular gene in a genome, the expression level of that gene would be double relative to a strain which has only one copy of the gene (all other things being equal).
HomeBrew on Tue Feb 22 11:00:31 2011 said:
The number of a particular gene present per genome does not change due to expression level -- expression level changes influence the number of RNA transcripts produced from the gene and, ultimately, how much of that gene's product (protein) is produced, but not the number of copies of the gene itself.
So, while expression level does not change the gene's copy number, the copy number of a gene in a genome can influence the expression level -- if you have two copies of a particular gene in a genome, the expression level of that gene would be double relative to a strain which has only one copy of the gene (all other things being equal).
Correct, altough you could make it even more complex with autoregulation: even if you have lets say 8 copies, you would still not get more gene product then the normal 5 copies (for ex.)
But I am not sure this if of any importance for you claritylight.
Agreed -- that was sort of why I put the "all other things being equal" disclaimer. Or gene dosage could cause lethality. Hell, effective copy number could be influenced by growth rate, too, but I'm not sure claritylight wants to get in that deep...
HomeBrew on Tue Feb 22 13:51:57 2011 said:
Agreed -- that was sort of why I put the "all other things being equal" disclaimer. Or gene dosage could cause lethality. Hell, effective copy number could be influenced by growth rate, too, but I'm not sure claritylight wants to get in that deep...
Ok. I had the idea that you indeed referred to it by saying all other things being equal, but wasnt sure.
And yes, probably she doesnt need to go so deep in it.
But if she does, she now knows there is more to it.