The Sirt6BAC transgenic mouse line was created by Dr. Roberto Coppari (University of Geneva). First, the ~185.7 kbp C57BL/6J mouse bacterial artificial chromosome (BAC) RP23-352G18 was obtained; containing the entire sirtuin 6 locus (Sirt6) as well as ~109 kbp of centromeric flanking sequences (including a portion of the Gna15 locus, several complete loci [Gna11, Aes, Tle2, Tle6, BC025920, Ankrd24] and predicted genes [Gm31878, Gm31936, Gm32024]) and ~70 kbp of telomeric flanking sequences (including the predicted gene Gm10778). The RP23-352G18 BAC DNA was modified only by insertion of an ampicillin resistance cassette, and the ~186.6 kbp construct was microinjected into the pronuclei of fertilized C57BL/6J embryos.
Founder animals were bred to C57BL/6J inbred mice for germline transmission, establishing three founder lines. Sirt6BAC founder line 1 was identified with two-to-four fold greater expression of SIRT6 compared to wildtype littermates. The donating investigator reports that Sirt6BAC transgenic mice from this founder line were maintained by breeding to wildtype (non-transgenic) siblings each generation for more than five generations, and then sent to Dr. Raul Mostoslavsky (Massachusetts General Hospital, Harvard Medical School) in 2014. There, the mice were bred once to C57BL/6NCrl females, and then maintained by breeding to wildtype (non-transgenic) siblings prior to sending to The Jackson Laboratory Repository in 2015 (see SNP results below). Upon arrival, sperm was cryopreserved. To establish our living colony, an aliquot of the frozen sperm was used to fertilize oocytes from C57BL/6J inbred females (Stock No. 000664).
In 2016, a 32 SNP (single nucleotide polymorphism) panel analysis, with 27 markers covering all 19 chromosomes and the X chromosome, as well as 5 markers that distinguish between the C57BL/6J and C57BL/6N substrains, was performed on the first generation rederived living colony at The Jackson Laboratory Repository. All the 27 markers throughout the genome suggested a C57BL/6 genetic background. 5 of 5 markers that determine C57BL/6J from C57BL/6N were found to be segregating in some mice (chromosomes 8 [~15.2 Mbp], 11 [~4.4 Mbp], 13 [~41.0 Mbp] and 15 [~57.6 Mbp]. As expected, these data suggest that the mice sent to The Jackson Laboratory Repository were on a mixed C57BL/6N;C57BL/6J genetic background.
