CaMK2a-tTA transgenic mice express the tetracycline-controlled transactivator protein (tTA) under regulatory control of the forebrain-specific calcium-calmodulin-dependent kinase II (Camk2a) promoter.
As described for Stock No. 007004, the CaMK2a-tTA transgene integrated into chromosome 12 causing a 508.12 Kb deletion that spans the 3' half of Vipr2 (vasoactive intestinal peptide receptor 2), the entire Wdr60 (WD repeat domain 60), Esyt2 (extended synaptotagmin-like protein 2), D430020J02Rik (RIKEN cDNA D430020J02 gene) and Ncapg2 (non-SMC condensin II complex, subunit G2) loci and the first two exons of Ptprn2 (protein tyrosine phosphatase, receptor type, N polypeptide 2). Homozygous mice will therefore have a functional knock-out of the deleted loci (Wdr60, Esyt2, D430020J02Rik, Ncapg2), and altered or null expression of Vipr2 and Ptprn2. Founder line 1 has a copy number of greater than 20 [Goodwin et al. 2019 Genome Res. 29:494].
Hemizygous mice are viable and fertile. When hemizygotes are mated to a second strain carrying a gene of interest under the regulatory control of a tetracycline-responsive promoter element (TRE; tetO), expression of the target gene can be blocked by administration of the tetracycline analog, doxycycline (dox). These mice are a "Tet-Off" tool that allow the inducible expression of genes in forebrain neurons, and may be useful in studying brain disorders such as Alzheimer's disease (when used in conjunction with Stock No. 005706, Stock No. 007049, Stock No. 007051, Stock No. 007052), Parkinson's disease (Stock No. 013583), or other neurodegenerative diseases.
Of note, mice expressing Tg(Camk2a-tTA)1Mmay on the C57BL/6 background exhibit resistance to tTA-induced neurotoxicity (dentate gyrus granule cell layer atrophy). All other backgrounds tested (FVB/NJ, CBA/J, 129X1/SvJ, C3H/HeJ, DBA/1J) exhibit varying levels of neurotoxicity (Han et al. 2012 J Neurosci 32:10574).
