B6J.B6N-Aldh7a1^{tm1c(EUCOMM)Hmgu}/BlrlJ

Stock number: 036172
Product name: Aldh7a1 floxed

Research areas: Metabolism Research, Neurobiology Research, Research Tools

Description

Exon 6 of the Aldh7a1 (aldehyde dehydrogenase family 7, member A1) gene is flanked by loxP sites in this conditional mutant strain. These mice may be useful in studies of lysine metabolism and pyridoxine-dependent epilepsy (PDE).

Detailed description

This strain was generated using embryonic stem cells provided by the International Knockout Mouse Consortium (IKMC). Aldh7a1 (aldehyde dehydrogenase family 7, member A1) encodes an aldehyde dehydrogenase involved in lysine catabolism. Mutations in ALDH7A1 are associated with pyridoxine-dependent epilepsy (PDE). PDE is a rare disease caused by a blockade of the lysine catabolism pathway and characterized by recurrent seizures, which can be controlled by pyridoxine (PN) and neurodevelopmental deficits. Exon 6 of the Aldh7a1 gene is flanked by loxP (floxed) sites in this conditional mutant strain. Loss of exon 6 results in a frameshift in exon 7 that introduces a premature stop codon and loss of gene expression. Heterozygous and homozygous floxed mice are healthy and fertile with no obvious phenotype.

When bred to mice with widespread Cre recombinase expression (B6.FVB-Tmem163^{Tg(ACTB-cre)2Mrt}/EmsJ, Stock No. 033984) knock-out offspring bred to homozygosity do not have an overt clinical phenotype and are viable to adulthood. However, when these mice are fed a high lysine diet they develop severe seizures and die quickly.

Development

C57BL/6N-derived JM8A3.N1 embryonic stem (ES) cells (clone HEPD0564_1_C06) bearing the Aldh7a1^{tm1a(EUCOMM)Hmgu} targeted allele were obtained from The European Conditional Mouse Mutagenesis Program (EUCOMM). This construct incorporates an FRT-lacZ-pA-loxP-neomycin-pA-FRT-loxP cassette in intron 5 and a loxP site in intron 6 of the mouse Aldh7a1 gene on chromosome 18. Targeted ES cells were injected into C57BL/6J blastocysts. Chimeric mice were crossed to C57BL/6J mice. Progeny were bred to B6J;B6N-Tg(CAG-Flpo)1Afst/Mmucd mice to excise the FRT-flanked lacZ and neo cassette leaving exon 6 flanked by loxP sites. Mice were bred to C57BL/6J mice for at least 5 generations and the flp allele was bred out. To establish our live colony, an aliquot of frozen sperm was used to fertilize C57BL/6J females (Stock No. 000664).

Allele

Symbol: Aldh7a1^{tm1c(EUCOMM)Hmgu}
Name: targeted mutation 1c, Helmholtz Zentrum Muenchen GmbH
MGI accession ID: MGI:6491214
Generation method: Targeted
Attributes: Conditional ready (e.g. floxed)
Marker symbol: Aldh7a1
Marker name: aldehyde dehydrogenase family 7, member A1
Marker synonyms: antiquitin; Atq1; D18Wsu181e; EPD; EPEO4; PDE
Chromosome: 18
Strain of origin: C57BL/6N-A^tm1Brd
Molecular note: The L1L2_Bact_P cassette was inserted at position 56681275 of Chromosome 18 upstream of the critical exon(s) (Build GRCm39). The cassette is composed of an FRT site followed by lacZ sequence and a loxP site. This first loxP site is followed by a neomycin resistance gene under the control of the human beta-actin promoter, SV40 polyA, a second FRT site and a second loxP site. A third loxP site is inserted downstream of the targeted exon(s) at position 56682076. The critical exon 6 is thus flanked by loxP sites. Flp-mediated recombination removed the lacZ and neomycin resistance gene and generated an exon 6 "conditional ready" (floxed) allele.