What could be the reason for a variegated expression pattern of my MHC-I transgene, in the whole litter, and positive/negative population per mouse?

My MHC-I transgene under MHC-I gene promoter, is either on or off per cell, leading to a positive and negative population in body, which is different in every mouse. This expression is unanimous...

06 June 2016 3,412 8 View