Taconic Biosciences, Inc. products

In order to selectively inactivate genes in a tissue-specific manner many laboratories have developed Cre transgenic mouse strains in which the Cre recombinase is expressed under the control of a tissue-specific promoter. The CD4-Cre Microinjected Mouse uses the mouse Cd4 promoter/enhancer/silencer, which first allows expression of CD4 as thymocytes enter the double positive stage. The silencer region extinguishes transgene expression at the double negative stage as well as in CD4-CD8+ mature thymocytes. This transgenic mouse shows a high degree of expression of the transgene in the thymus and the recombinase has been shown to bring about the selective deletion of genes flanked by loxP targeting sequences in most thymocytes at the double positive stage. The mice were again made homozygous for the transgene by intracrossing followed by selection using test crosses to outbred mice.

Origin: The B6.SJL Congenic model was developed by Boyse et al in 1975 by intercrossing C57BL/6Boy mice to SJL/J mice. Taconic received stock from the NIAID in 1995. The mice were derived by embryo transfer into the NIAID Transgenic Mouse Repository. The mice were backcrossed by Boyse to a C57BL/6Boy inbred background to select for SJL antigen type (now referred to as Ptprca or Ly5.1). Refreshed in 2007 from NIAID stock. Further backcrossed to the C57BL/6NTac background to NE8.

Origin: The B6129F1 hybrid model is developed by intercrossing C57BL/6NTac female mice to 129S6/SvEvTac male mice from Taconic US`s commercial colonies.