The BLG-Cre transgene was designed by Dr. Alan R. Clarke (while at University Medical School, Edinburgh, United Kingdom) to have Cre recombinase under the control of the sheep mammary gland specific promoter of the ovine beta-lactoglobulin (BLG) gene. The construct included exon 1 of sheep BLG, and a Cre recombinase with a modified initiation codon and a polyadenylation signal (polyA). The construct was microinjected into the pronuclei of (CBA x C57BL/6) fertilized oocytes, and mice from founder line 74 were identified and bred to C57BL/6 mice. These mice were intercrossed to establish a colony of BLG-cre mice on a mixed background.
BLG-Cre transgenic mice were bred to C57BL/6;129S7-Trp53tm1Brd and C57BL/6;129-Brca1tm1Aash mice, and the resulting triple mutant mice were sent to The Jackson Laboratory Repository as Stock No. 012620. Upon arrival, some mice were selectively bred with wildtype mice from the colony or with C57BL/6J inbred mice (Stock No. 000664) to generate this single mutant colony harboring only the BLG-Cre transgene (as Stock No. 017836).
