These Slc20a1 knockout mice exhibit vasculature defects early in development that result in embryos being completely resorbed by E14. This strain may be useful for studying inorganic phosphate transport regulation in embryonic vascular development.
Cecilia M. Giachelli, University of Washington
A targeting vector was designed to remove exons 3-4 of the solute carrier family 20, member 1 (Slc20a1 or inorganic phosphate transporter-1 PiT-1) gene, in the epiblast, yolk sac mesoderm, and amnion, abolishing gene function. Mice that are heterozygous for this PiT-1Δe3,4 allele are viable, fertile, normal in size and do not display any gross physical or behavioral abnormalities, while homozygotes display an embryonic lethal phenotype. PiT-1, a ubiquitously expressed transmembrane type III sodium-dependent transporter, is associated with vascular calcification in many diseases, including diabetes, chronic kidney disease (CKD), and Werner Syndrome. The yolk sacs of homozygous embryos reveal a decrease in the superficial vasculature and appear severely anemic by E10.5. By E12.5, the embryos display significant growth retardation and anemia, leading to hypoxia, nutrient deprivation, growth arrest, and lethality. These homozygous PiT-1Δe3,4 embryos are completely resorbed by E14.5.
A targeting vector was designed to insert a loxP site upstream of exon 3, and a frt-flanked and loxP-flanked neomycin resistance (neo) cassette (in opposite orientation to the gene) was placed downstream of exon 4 of the solute carrier family 20, member 1 (Slc20a1 or inorganic phosphate transporter-1 PiT-1) gene. The construct was electroporated into (C57BL/6N x 129S/SvEv)-derived iTLBA1 embryonic stem (ES) cells. Correctly targeted ES cells were injected into blastocysts and the chimeric male was bred to Tg(Sox2-cre)1Amc/J mice on a C57BL/6 x CBA background, to drive recombination of loxP sites in the epiblast, yolk sac mesoderm, and amnion. The resulting offspring contained multiple gene rearrangments; intact floxed-exons 3-4, intact floxed-neo cassette, or excision of exons 3-4 along with the neo cassette. PiT-1Δe3,4 offspring exhibiting removal of exons 3-4 along with the neo cassette, were backcrossed to C57BL/6 for at least 10 generations. Upon arrival at The Jackson Laboratory, mice were bred to C57BL/6J inbred mice (Stock No. 000664) for at least one generation to establish the colony.
|Allele Name||targeted mutation 1.2, Cecilia M Giachelli|
|Allele Type||Targeted (Null/Knockout)|
|Gene Symbol and Name||Slc20a1, solute carrier family 20, member 1|
|Strain of Origin||(C57BL/6NTac x 129S6/SvEvTac)F1|
|Molecular Note||Cre mediated recombination removed exons 3 and 4. The absence of transcripts containing exon 2 was confirmed by semi-quantitative RT-PCR analysis on E11.5 embryo extracts.|
|Mutations Made By|| |
Cecilia Giachelli, University of Washington
When maintaining a live colony, heterozygous mice may be bred to wildtype from the colony or to C57BL/6J inbred mice (Stock No. 000664). Homozygotes exhibit embryonic lethal phenotype ~ E10.5.
When using the B6.Cg-Slc20a1tm1.2Cmg/J mouse strain in a publication, please cite the originating article(s) and include JAX stock #013717 in your Materials and Methods section.