Transgenic reporter constructs

[milstone]

The general dogma is that "vector" sequences can (that is, have 
occasionally been observed to) alter the specificity of expression 
driven by particular regulatory sequences in transgenic mice. My 
impression is that the effect is quite variable with different 
regulatory elements and that few investigators are currently interested 
in systematically studying this aspect of transgenesis. Founders with 
faithful expression can definately be generated at high frequency 
without incorporating "protective" cloning vector flanking sequences in 
transgenic constructs. It seems to me that the potential benefits of 
including extra sequence are not very great.