why DNA from mouse tails are used for genotyping ? - need to understand the basic concept (Aug/08/2008 )
I have a silly question, I believe,
why DNA from mouse tail is used for genotyping the transgenic, when the promoter driving the expression of the trasngene is tissue specific, which is not tail in my case?
can someone help me understand this basic concept?
The transgene should end up in every cell. If you just want to see if the transgene is there, then it doesn't matter what cells you gentotype. If you want to see if the transgene is transcribed, then you have to test the tissue where that happens, which depending on what promoter you've used, will probably only happen in certain tissues. Genotyping only looks at the DNA, but to determine if the transgene is transcribed, then you need to look at the RNA that is the product of the transcription. Clear?
I undesrtand now since the transgene will get randomly intergrated in the genome and thus on division and proliferation will have in every cell, but since promoter is tissue specific, transcription wont occur everywhere, right ?
thanks a lot !