B6.Cg-Col4a5^tm1Yseg/J

Stock number: 006183
Product name: Col4a5 KI
Research areas: Endocrine Deficiency Research, Internal/Organ Research, Mouse/Human Gene Homologs, Research Tools

Description

These targeted knock-in mice develop kidney abnormalities, die prematurely, and serve as a model of human X-linked Alport syndrome.

Detailed description

Heterozygous females and hemizygous males for the targeted mutation are viable, fertile, normal in size and do not display any gross physical or behavioral abnormalities. Immunofluorescence analysis of kidney tissue from mutant male mice does not detect gene product (protein), but in kidney from mutant female mice a mosaic pattern of gene product (protein) is detected (due to X-inactivation). RNase protection assay analysis of kidney tissue from mutant male mice detects a significantly lower level than wildtype. Hemizygous male and heterozygous female mice develop progressive kidney disease. By 7 weeks of age, 97% of mutant male mice and 78% of heterozygous female mice exhibit proteinuria. Histological analysis of kidneys from mutant male mice at 4 weeks of age reveals thickened capillary walls and mesangial hypercellularity. The pathology progresses to interstitial inflammation, glomerular abnormalities, and focal sclerosis. Electron microscopic examination of glomerular basement membrane ultrastructure shows lamellation and splitting abnormalities. Female mice heterozygous for the mutation exhibit similar progressive kidney disease but at later onset than the hemizygous males. These mice do not contain the neo selection cassette. This mutant mouse strain may be useful in studies of X-linked Alport syndrome (XLAS).

Homozygous females were found to be viable and fertile in colonies at The Jackson Laboratory, though no phenotype information was collected. (June, 2007)

Development

A targeting vector containing a loxP site flanked neomycin resistance gene and a point mutation was used to insert a G213T transversion into exon 1. The construct was electroporated into 129SvJ derived ESVJ-1182 embryonic stem (ES) cells. Correctly targeted ES cells were injected into C57BL/6 blastocysts. The resulting chimeric animals were crossed to FVB/N-Tg(ACTB-cre)2Mrt/J (Stock No. 003376) mice to remove the neo selection cassette and then backcrossed to C57BL/6 for 15 generations.

Allele

Symbol: Col4a5^tm1Yseg
Name: targeted mutation 1, Yoav Segal
MGI accession ID: MGI:3609047
Generation method: Targeted
Attributes: Null/Knockout; Humanized sequence; Modified isoform(s)
Marker symbol: Col4a5
Marker name: collagen, type IV, alpha 5
Chromosome: X
Strain of origin: 129X1/SvJ
Molecular note: A targeting construct was designed to insert a G to T nucleotide transversion into exon 1. This mutation converts codon 5 from a glycine to a stop codon (G5X). Expression of the alpha5(IV) chain was lost in mutant kidneys from males. Basement membrane expression of the alpha 3(IV) chain was lost as well as that of the alpha6(IV) chain. Expression of alpha1(IV) and alpha2(IV) was conserved. Expression of the alpha5(IV) and alpha3(IV) chains in kidneys from females was mosaic, reflecting X-inactivation.