C57BL/6-Tg(Camk2a-Bdnf)A9Stl/J

Stock number: 006579
Product name: BDNF
Research areas: Neurobiology Research, Research Tools, Sensorineural Research

Description

These BDNF mice express a transgene containing the rat brain-derived neurotrophic factor driven by the Camk2a promoter affecting maturation and plasticity of the visual cortex.

Detailed description

Hemizygous mice are viable and fertile, although the donating investigator reports that hemizygous mice have breeding problems likely resulting from a social anxiety-related phenotype. These "BDNF (line A9)" mice express the rat brain-derived neurotrophic factor (BDNF) primarily in forebrain regions, including the neocortex and hippocampus. Weak transgenic BDNF expression is detected also in cerebellum. Within the primary visual cortex, transgene expression is highest in the superficial layers. Hemizygous mice exhibit accelerated maturation of GABAergic innervation and inhibition, earlier termination of the critical period for ocular dominance plasticity, and accelerated development of visual acuity. These transgenic mice may be useful for studies involving BDNF overexpression and synaptic maturation and plasticity in the visual cortex.

Development

A rat Bdnf cDNA sequence (modified with a Kozac sequence inserted in front of the translation initiation codon) and a SV40 intron and polyadenylation sequence was placed downstream of the 8.5 kb promoter region from mouse Camk2a. This transgene was injected into the pronuclei of C57BL/6 embryos. The donating investigator reported that the resulting chimeric founders (line A9) were subsequently bred to C57BL/6 mice (see SNP note below) and maintained on that genetic background for many generations prior to arrival at The Jackson Laboratory.

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 rederived living colony at The Jackson Laboratory Repository. While the 27 markers throughout the genome suggested a C57BL/6 genetic background, 3 of 5 markers that determine C57BL/6J from C57BL/6N were found to be segregating. These data suggest the mice sent to The Jackson Laboratory Repository were on a mixed C57BL/6J ; C57BL/6N genetic background.

Allele

Symbol: Tg(Camk2a-Bdnf)A9Stl
Name: transgene insertion A9, Susumu Tonegawa
MGI accession ID: MGI:3709467
Generation method: Transgenic
Attributes: Inserted expressed sequence
Marker symbol: Tg(Camk2a-Bdnf)A9Stl
Marker name: transgene insertion A9, Susumu Tonegawa
Chromosome: UN
Strain of origin: (C57BL/6 x DBA/2)F2
Expressed genes: Bdnf,brain-derived neurotrophic factor,rat
Molecular note: The transgene construct has the rat Bdnf cDNA sequence, with a Kozak sequence inserted in front of the translation initiation site, controlled by the mouse Camk2a promoter. The SV40 intron/polyA sequence was inserted the 3' to the Bdnf cDNA. ISH demonstrated that Bdnf overexpression is mainly restricted to the forebrain regions, including all of the neocortex, parts of the hippocampus, amygdala and striatum.