These Pemt knock-out mice exhibit a lack of phosphatidylethanolamine N-methyltransferase (PEMT) activity.
Dr. Dennis E. Vance, University of Alberta
Mice homozygous for the Pemttm1J are viable and fertile. Pemt encodes an enzyme that converts phosphatidylethanolamine to phosphatidylcholine. Homozygotes completely lack PEMT activity and are no longer able to catalyze this reaction. Homozygotes are indistinguishable from controls in terms of development, behavior, and fecundity. Hepatocyte morphology, plasma lipid levels, and bile composition are normal. However, feeding homozygotes a choline deficient (CD) diet causes rapid onset of a severe liver pathology. Mice lose weight, develop grossly enlarged and pale colored livers, develop bright yellow plasma, and their gall bladders become engorged. In addition, a 50% decrease in liver phosphatidylcholine concentration and greater than 90% decrease in plasma triacylglyceride and cholesterol levels is observed in homozygotes on the CD-deficient diet.
A sequence-replacement type gene targeting vector was constructed from a 6-kb BamHI subclone of gamma clone 3 containing exon 2 of the mouse Pemt2 gene. A cassette containing a neomycin-resistance gene (neo) driven by the Pgk promoter was inserted at unique XhoI and BclI sites in the subclone, replacing the majority of exon 2, including the translation start site, and the extreme 5' end of intron 1.
|Allele Name||targeted mutation 1, Jackson|
|Allele Type||Targeted (Null/Knockout)|
|Allele Synonym(s)||Pempt2-; Pemt-|
|Gene Symbol and Name||Pemt, phosphatidylethanolamine N-methyltransferase|
|Strain of Origin||129P2/OlaHsd|
|Molecular Note||A PGK neomycin cassette replaces the majority of exon 2, including the translation start site and the extreme 5' end of the intron. Lack of protein in homozygous mutant mice was demonstrated by immunoblot assays on liver homogenates, using a rat antibody from the C terminal end of the protein. Enzymatic activity was also abolished in homozygous mutant animals.|
|Mutations Made By|| |
Dr. Dennis Vance, University of Alberta
This strain is maintained as homozygous sibling matings.
When using the Pempt2- mouse strain in a publication, please cite the originating article(s) and include JAX stock #003187 in your Materials and Methods section.