C57BL/6-Itga4^tm1Mshi/J

Stock number: 010501
Research areas: Cell Biology Research, Immunology, Inflammation and Autoimmunity Research

Description

This targeted mutation of the integrin alpha 4 (Itga4) gene exhibits impaired lymphocyte transmigration and homing to the gut. This mutant mouse strain may be useful in studies of leukocyte migration and homing.

Detailed description

Mice homozygous for the targeted mutation are viable, fertile, normal in size and do not display any gross physical or behavioral abnormalities. Lymphocytes exhibit increased basal adhesiveness to VCAM1 and MAdCAM1 under physiological conditions as well as reduced transmigration across VCAM1 and MAdCAM1 substrates and endothelial monolayers under shear stress. Homing of mutant lymphocytes to the gut is reduced by approximately 50%. In addition, fewer lymphocytes are found in the gut and Peyer's Patches are smaller in size than wild-type. This mutant mouse strain may be useful in studies of leukocyte migration and homing.

Development

A targeting vector was designed to contain exons 26 and 27, an engineered Xba1 site, an ACN cassette, and exon 28, respectively. Exon 28 contains nucleotide mutations to generate an amino acid substitution of alanine for arginine. The loxP-flanked ACN cassette contains the neomycin resistance gene and Cre recombinase gene under the control of the sperm-specific angiotensin-converting enzyme promoter. Cre-mediated recombination during spermatogenesis of chimeric males removes the cassette leaving a single loxP- site between exons 27 and 28. The construct was electroporated into C57BL/6-derived Bruce-4 embryonic stem (ES) cells. Correctly targeted ES cells were injected into BALB/c blastocysts, and the resulting chimeric males were crossed to C57BL/6 females. Homozygotes were generated and then maintained by intercross prior to arrival at The Jackson Laboratory.

Allele

Symbol: Itga4^tm1Mshi
Name: targeted mutation 1, Motomu Shimaoka
MGI accession ID: MGI:3830623
Generation method: Targeted
Attributes: Not Applicable
Marker symbol: Itga4
Marker name: integrin alpha 4
Chromosome: 2
Strain of origin: B6.Cg-Thy1^a
Molecular note: Exon 28 was replaced with one in which nucleotide substitutions resulted in amino acid substitution of GFFKA for GFFKR. This sequence is involved in the formation of a membrane-proximal salt bridge necessary for inactivation. A self-excising neo cassette was inserted upstream of exon 28 and subsequently deleted in chimeras.