FVB;129-Ada^tm1Mw Tg(PLFSADA)2465Rkmb/J

Stock number: 003297
Product name: ada containing ADA minigene
Research areas: Developmental Biology Research, Immunology, Inflammation and Autoimmunity Research, Internal/Organ Research, Metabolism Research

Description

These double mutant mice carry a null allele of Ada and a transgene containing a murine cDNA minigene of Ada, founder line 2465. Transgenic ADA expression in the prenatal placenta and postnatal forestomach rescues the lethal phenotype of homozygous null mice, and the mice exhibit partial immune deficiency.

Detailed description

Mice homozygous for the Ada^tm1Mw targeted mutation die perinatally. They show defects in purine metabolism and develop liver cell degeneration. Death is most likely the result of accumulation of ADA precursors. In this strain (FVB;129-Ada^tm1Mw Tg(PLFSADA)2465Rkmb/J - Stock No. 003297), mice carry a transgene overexpressing ADA in both the placenta and forestomach. Double mutant mice homozygous for the null Ada allele live a normal lifespan displaying only a partial immune deficiency and developing less severe pulmonary inflammation.

Mice from the double mutant strain FVB,129- Ada^tm1Mw Tg(PLADA)4118Rkmb/J (Stock No. 003265) express ADA in the placenta alone. These mice are rescued from embryonic lethality, but die from severe respiratory distress by three weeks of age. These mice exhibit a severe combined immunodeficiency and develop a severe lung eosinopilia reminiscent of that seen in humans with asthma. Abnormalities are also found in the bone and kidney.

Development

The original adenosine deaminase Ada knockout mice were generated by the insertion of the neomycin gene into exon 5 of the murine Ada gene. The targeting construct was electroporated into 129S7/SvEvBrd-derived AB1 embryonic stem (ES) cells.

This transgenic strain was made with a 36 bp deletion in the endogenous promoter directing Ada expression to the placenta and forestomach. The transgene was injected into the pronuclei of FVB/N mouse oocytes.

Allele

Symbol: Tg(PLFSADA)2465Rkmb
Name: transgene insertion 2465, Michael R Blackburn
MGI accession ID: MGI:2681791
Generation method: Transgenic
Attributes: Inserted expressed sequence
Marker symbol: Tg(PLFSADA)2465Rkmb
Marker name: transgene insertion 2465, Michael R Blackburn
Chromosome: UN
Strain of origin: FVB/N
Expressed genes: Ada,adenosine deaminase,mouse, laboratory
Molecular note: A construct was made that included a 2.8 kb genomic fragment containing the endogenous polyadenylation sequence, intron 11, and ~2kb of 3'-untranslated region and 3' flanking region of the gene. The endogenous promoter was replaced with a promoter containing a 36-bp deletion in the 5'-untranslated region. This resulted in a construct that contained the gene's regulatory elements, allowing expression in the placenta prenatally and the forestomach postnatally, while the 36-bp deletion in the promoter allowed distinction of this transcript from that of native transcript. RNase protection showed transgene transcript in placentas, but not fetuses, of transgenic animals. Enzymatic activity of the protein product was increased in the placenta, but not in the fetus, of transgenic mice compared to nontransgenic animals.

Allele

Symbol: Ada^tm1Mw
Name: targeted mutation 1, Maki Wakamiya
MGI accession ID: MGI:1857117
Generation method: Targeted
Attributes: Null/Knockout
Marker symbol: Ada
Marker name: adenosine deaminase
Chromosome: 2
Strain of origin: 129S7/SvEvBrd-Hprt⁺
Molecular note: A neomycin selection cassette was inserted into exon 5. Activity assays demonstrated that no functional protein was made from this allele in homozygous mice.
General note: Phenotypic Similarity to Human Syndrome: Pulmonary Hypertension associated with Chronic Obstructive Pulmonary Disease J: 231559.