129S1.B6(C3)-Slc40a1^ffe/ZohnJ

Stock number: 029246
Product name: flatiron, Fpn^ffe
Research areas: Hematological Research, Metabolism Research, Research Tools

Description

This ENU-generated flatiron (ffe) mutation of Slc40a1 creates a missense mutant allele that results in mislocalization of the encoded iron transporter. These mice may be suitable as a model Hemochromatosis Type IV (or Ferroportin Disease).

Detailed description

The targeted Slc40a1 gene encodes the iron transporter ferroportin. Missense mutations in this gene have been associated with hemochromatosis type 4. These ENU-generated flatiron (ffe) Slc40a1 mutants carry a missense A>G nucleotide substitution at position 95 in the coding sequence, resulting in an H32R substitution in the signal sequence. The H32R amino acid substitution results in mislocalization of the ferroportin protein and acts as a dominant negative. Heterozygotes are viable and fertile. Homozygotes on the 129S1/SvImJ background have a mid-gestational lethal phenotype and severe anemia. 6 month old heterozygotes exhibit mild anemia, low transferrin saturation, high serum ferritin (10 fold at 6 months of age that increases with age), and excessive iron accumulation in Kupffer cells. Macrophages isolated from heterozygous mice exhibit impaired iron export. During backcrossing, the Y chromosome may not have been fixed to the 129S1/SvImJ genetic background.

Development

Male C57BL/6J mice were treated with N-ethyl-N-nitrosourea (ENU) and then bred to C3H females. The resulting F1 males were crossed to C3H females, and female offspring mated back to F1 males to homozygose any deleterious mutations. A mutagenesis screen was then performed to select mice with mutations effecting neural tube morphology at embryonic day 12.5. Following establishment of the line, the genetic mutation was identified by positional cloning followed by sequencing of candidate genes. Sequencing of solute carrier family 40 (iron-regulated transporter), member 1 (Slc40a1) gene identified a A>G nucleotide substitution at position 95 in the coding sequence, resulting in an H32R substitution in the signal sequence.

The donating investigator reported that these mice were backcrossed to 129S1/SvImJ mice for at least 10 generations. During backcrossing, the Y chromosome may not have been fixed to the 129S1/SvImJ genetic background.

Upon arrival, sperm was cryopreserved. To establish our live colony, an aliquot of frozen sperm was used to fertilize 129S1/SvImJ oocytes (Stock No. 002448).

Allele

Symbol: Slc40a1^ffe
Name: flatiron
MGI accession ID: MGI:3662903
Generation method: Chemically induced (ENU)
Marker symbol: Slc40a1
Marker name: solute carrier family 40 (iron-regulated transporter), member 1
Chromosome: 1
Strain of origin: C57BL/6J
Molecular note: This allele contains an A to G transition at position 95 in the coding sequence, resulting in an H32R substitution in the signal sequence.