B6;129S-Sele^tm2Hyn Sell^tm4Hyn/J

Stock number: 003806
Product name: EL-

Description

These double knock-out mice exhibit a diminished response in neutrophil recruitment to the peritoneum in response to thioglycollate.

Detailed description

Mice that are homozygous null for the Sele and Sell genes are viable, fertile, normal in size and do not display any gross physical or behavioral abnormalities. No Sele or Sell gene products (mRNA or protein) are detected. A slightly diminished response in neutrophil recruitment to the peritoneum in response to thioglycollate is observed, as is a diminished ability to interact with the venular endothelium resulting in increased "rolling" along the vessel wall. These mice are suitable for use in research applications studying leukocyte homeostasis, infectious diseases and inflammation.

Development

Sequential mutation by homologous recombination was utilized to replace the Sele and Sell genes with drug-resistance genes for hygromycin and puromycin (respectively) in 129S2/SvPas-derived D3 embryonic stem (ES) cells. This approach was necessary because the Sele and Sell genes are too closely linked for double-deficient animals to be generated by mating single-deficient animals. Correctly targeted ES cells were injected into C57BL/6 blastocysts and chimeric offspring obtained.

Allele

Symbol: Sell^tm4Hyn
Name: targeted mutation 4, Richard Hynes
MGI accession ID: MGI:3839979
Generation method: Targeted
Attributes: Null/Knockout
Marker symbol: Sell
Marker name: selectin, lymphocyte
Chromosome: 1
Strain of origin: 129S2/SvPas
Molecular note: The three selectin genes, Sele, Sell, and Selp, are found within a 300 kb genomic region. To generate double knockouts, ES cells heterozygote for the Selp^tm1Hyn and Sele^tm2Hyn null alleles in trans to each other were targeted a third time. A PGK-puro cassette was used to delete a 2.1 kb region containing the exons encoding the lectin domain and most of the epidermal growth factor domain. Flow cytometric analysis of homozygote leukocytes showed an absence of the L-selectin and E-selectin protein while P-selectin express was unaffected. Thus, this targeted mutation occurred in cis with the Sele^tm2Hyn allele and in trans with the Selp^tm1Hyn allele. Due to their genomic proximity, the Sell^tm3Hyn and Sele^tm2Hyn alleles should propagate together through the offspring.

Allele

Symbol: Sele^tm2Hyn
Name: targeted mutation 2, Richard Hynes
MGI accession ID: MGI:3839963
Generation method: Targeted
Attributes: Null/Knockout
Marker symbol: Sele
Marker name: selectin, endothelial cell
Chromosome: 1
Strain of origin: 129S2/SvPas
Molecular note: A modified D3 ES cell line heterozygous for the Selp^tm1Hyn allele was targeted a second time. The exons encoding the signal peptide, lectin domain, and a portion of the epidermal growth factor domain were replaced by the insertion of a PGK-hygro cassette. Both Northern and RT-PCR analysis revealed an absence of normal mRNA for E-selectin but the presence of mRNA for P-selectin in extracts from cardiac and pulmonary tissue of homozygous mutant mice. This targeted mutation occurred in trans with the Selp^tm1Hyn mutation and were subsequently bred apart.