FVB.129P2(B6)-Dmpk^tm1Bew/CathJ

Stock number: 040713
Product name: FVB.Dmpk KO
Research areas: Cardiovascular Research, Neurobiology Research, Research Tools

Description

FVB.Dmpk knock-out (KO) mice have a hygroB cassette replacing the majority of the dystrophia myotonica-protein kinase (Dmpk) gene, including the ATG start site, on a congenic FVB/N-congenic background. This mutation results in complete loss of DMPK protein. These mice may be useful for studying the role of DMPK in muscle function, calcium homeostasis and synaptic plasticity.

Of note, this Dmpk KO allele on a C57BL/6N congenic background (Stock No. 040573) has also been made available.

Detailed description

The dystrophia myotonica-protein kinase (Dmpk) gene codes for an enzyme that is highly expressed in cardiac, skeletal and smooth muscle. While the physiological role of this kinase is not clearly defined, it may be involved in regulating muscle function, glucose metabolism, and synaptic plasticity. Mutations in this gene, specifically trinucleotide repeat expansions in the UTR, result in myotonic dystrophy type 1. These FVB.Dmpk knock-out (KO) mice have a hygroB cassette replacing the majority of the Dmpk gene, including the ATG start site, on a FVB/N-congenic background. This mutation leads to complete loss of DMPK protein.

Homozygous mice are viable and fertile with no overt phenotype under baseline conditions. Homozygous mice do display a mild cardiac phenotype after transverse aortic constriction (TAC). FVB.Dmpk KO mice may be useful for studying the role of DMPK in cardiac, skeletal and smooth muscle function, calcium homeostasis and synaptic plasticity.

Of note, this Dmpk KO allele on an C57BL/6N-congenic background (Stock No. 040573) has also been made available.

Development

The Dmpk knock-out (KO) allele, originally generated by Dr. Be Wieringa, was designed to replace a 4.5 kb segment of the dystrophia myotonica-protein kinase (Dmpk) gene, including the ATG start site, with a Hygromycin B resistance cassette via homologous recombination. The construct was electroporated into 129P2/OlaHsd-derived E14 embryonic stem (ES) cells. Correctly targeted ES cells were injected into recipient blastocysts. Chimeric mice were bred to C57BL/6 mice to confirm germline transmission. Resulting Dmpk KO mice were maintained on a mixed B6;129 genetic background.

Dr. Charles Thornton acquired some of the Dmpk KO mice, on a mixed B6;129 background, and backcrossed them onto the FVB/NTac genetic background (>99.7% congenic) using a marker-assisted, speed-congenic approach. To establish a live colony, an aliquot of frozen sperm was used to fertilize FVB/NJ (Stock No. 001800) oocytes.

Allele

Symbol: Dmpk^tm1Bew
Name: targeted mutation 1, Be Wieringa
MGI accession ID: MGI:3054407
Generation method: Targeted
Attributes: Null/Knockout
Synonyms: Dmpk^-
Marker symbol: Dmpk
Marker name: dystrophia myotonica-protein kinase
Marker synonyms: DM; DM1; Dm15; DM1PK; DMK; MDPK; MT-PK
Chromosome: 7
Strain of origin: 129P2/OlaHsd
Molecular note: A 4.5 kb segment, including the ATG start site ant 10 of the 11 conserved kinase domains, was replaced with a hygroB cassette via homologous recombination. Northern and western blot analysis confirmed the absence of mRNA and protein. Recombination also disrupted the polyadenylation signal of the upstream gene, Dmwd, resulting in production of a larger transcript but no significant change in expression level.