STOCK Ntrk1^tm1Apat/DnJ

Stock number: 004837
Product name: TkrA^{τlacZ
Research areas: Developmental Biology Research, Neurobiology Research}

Description

This allele has a tau-lacZ sequence inserted into the endogenous start site in place of exon 1, resulting in a null allele with an expressed reporter.

Detailed description

This allele has a tau-lacZ sequence inserted into the endogenous start site in place of exon 1, resulting in a null allele with an expressed reporter. Staining of heterozygotes at 2 days of age shows expression in dorsal root ganglion cell bodies and projections in dorsal spinal cord and skin. Homozygotes have a drastic reduction in the number of L4 and L5 dorsal root ganglion neurons, with only 8% of wildtype numbers for L5, yet normal numbers of parvalbumin positive L5 neurons. Dorsal root ganglion neurons in these homozygotes lack expression of the NTRK1-type neuronal proteins CALCA, TRPV1, and TRPM8, and staining for the NTKR3-type neuronal markers parvalbumin and ER81 shows normal levels of staining. Thus, there are normal numbers of NTRK3+ proprioceptive neurons but a lack of NTRK1-type nociceptive/thermoceptive sensory neurons due solely to the absence of NTRK1. Homozygotes die prematurely.

Development

The Ntrk1^tm1Apat mutation was generated in 129S1-derived CJ7 embryonic stem cells and a chimera or the offspring of a chimera was bred to FVB/N-Tg(ACTB-cre)2Mrt/J mice to excise the neomycin selection cassette and heterozgyotes were then bred to C57BL/6. In 2003 heterozygotes were shipped to Muriel Davisson at The Jackson Laboratory and bred to C57BL/6J for hysterectomy re-derivation. The line was subsequently bred to C57BL/6JEiJ for two consecutive generations then embryos were generated for cryopreservation from C57BL/6J females bred to heterozygous N2 males.

Allele

Symbol: Ntrk1^tm1Apat
Name: targeted mutation 1, Ardem Patapoutian
MGI accession ID: MGI:2678328
Generation method: Targeted
Attributes: Reporter; Null/Knockout
Marker symbol: Ntrk1
Marker name: neurotrophic tyrosine kinase, receptor, type 1
Chromosome: 3
Strain of origin: 129S1/Sv-Oca2⁺ Tyr⁺ Kitl⁺
Expressed genes: lacZ,beta-galactosidase,E. coli
Site of expression: X-gal staining indicated expression of lacZ in dorsal root ganglia and skin in heterozygotes
Molecular note: A targeting vector containing tau-lacZ, SV40 polyA and floxed neo was inserted immediately downstream of the ATG in exon 1. Crossing with Actb-cre mice excised the floxed neo. Southern blot confirmed recombination. X-gal staining indicated expression of lacZ in dorsal root ganglia and skin in heterozygotes.