The transgene construct contained a 3.4 kb fragment of the cre recombinase sequence dowstream of the 1.5 kb rat Abpa promoter. This was followed by the metallothionein I (MT-1) sequence with polyA signal. The purified, linearized construct was injected into fertilized B6D2F1 oocytes. 10 founders were obtained, with 9 showing testicular cre mRNA expression. One line was propagated. (J:157337)