B6;129-Eif2s1^tm1Rjk/J

Stock number: 017601
Product name: eIF2alpha^S51A
Research areas: Apoptosis Research, Cell Biology Research, Developmental Biology Research, Diabetes and Obesity Research, Endocrine Deficiency Research, Metabolism Research

Description

These Eif2s1 knock-out mice lack translational and transcriptional regulation in the endoplasmic reticulum. These mice maybe useful in diabetes research.

Detailed description

The Eif2a^S51A mutation in these mice prevents phosphorylation of the α subunit of eIF2. Phosphorylation of eIF2α in the endoplasmic reticulum (ER) is required for translational regulation, transcriptional induction, and survival in response to ER stress. EIF2α translational regulation is also required for the maintenance of blood glucose and pancreatic insulin content. Homozygotes die within 18 hr after birth due to hypoglycemia associated with defective gluconeogenesis. Homozygous mutant embryos and neonates displayed a deficiency in pancreatic β cells and an increase in circulating insulin. Heterozygotes are viable and fertile. On a high fat diet, heterozygous mice develop diabetes due to unregulated proinsulin translation. These mice also exhibit defective ER cargo trafficking, increased oxidative damage, reduced expression of stress response and beta-cell-specific genes, and apoptosis.

Development

Three base pair substitutions were introduced into exon 2 of the mouse eIF2α (Eif2s1) resulting in a single amino acid substitution of serine to alanine at codon 51 (S51A) within the phosphorylation site of the protein. A loxP-flanked neo cassette in reverse-orientation to the gene was inserted 200 bp upstream of exon 2. The construct was electroporated into (129X1/SvJ x 129S1/Sv)F1-Kitl⁺-derived R1 embryonic stem (ES) cells. Correctly targeted ES cells were injected into recipient C57BL/6 blastocysts and chimeric males were bred with C57BL/6 females to establish the colony. Mutant mice were bred with ZP3-Cre transgenic mice (on a C57BL/6 genetic background) to remove the neo selection cassette. The donating investigator reported that these eIF2α^S51A mice were bred to C57BL/6J mice for at least ten generations (see SNP note below), and the ZP3-Cre transgene was removed. Upon arrival at The Jackson Laboratory Repository, mice were bred to C57BL/6J inbred mice (Stock No. 000664) for at least one generation to establish the colony.

A 32 SNP (single nucleotide polymorphism) panel analysis, with 27 markers covering all 19 chromosomes and the X chromosome, as well as 5 markers that distinguish between the C57BL/6J and C57BL/6N substrains, was performed on the rederived living colony at The Jackson Laboratory Repository. 2 the 27 markers throughout the genome were segregating between B6J and 129, suggesting an incomplete backcross. Also, 4 of 5 markers that determine C57BL/6J from C57BL/6N were found to be segregating. These data suggest the mice sent to The Jackson Laboratory Repository were on a mixed C57BL/6J ; C57BL/6N genetic background.

Allele

Symbol: Eif2s1^tm1Rjk
Name: targeted mutation 1, Randal J Kaufman
MGI accession ID: MGI:2388264
Generation method: Targeted
Attributes: Not Specified
Synonyms: eIF2alpha^S/A; eIF2alpha^S51A
Marker symbol: Eif2s1
Marker name: eukaryotic translation initiation factor 2, subunit 1 alpha
Chromosome: 12
Strain of origin: (129X1/SvJ x 129S1/Sv)F1-Kitl⁺
Molecular note: A serine to alanine substitution at a phosphorylation site at position 51 (S51A) of exon 2 was introduced, and a floxed neomycin resistance cassette was inserted into the upstream intron for positive selection. The floxed neo cassette was removed by cre-mediated recombination leaving behind a single loxP site and the S51A mutation. Western blot analysis of mouse embryonic fibroblasts derived from homozygous mutant animals confirmed expression of the mutant allele.