Why am I not seeing the Cre activity I expect?

I am using the B6;129S6-Chattm2(cre)Lowl/J mouse from Jackson and crossing it to B6.129X1-Gt(ROSA)26Sortm1(EYFP)Cos/J, and while I see beautiful expression of YFP in the spinal cord, I see fewer...

28 June 2013 9,690 5 View