B6.129-Lcp2^tm1Gak/J

Stock number: 018860
Product name: SLP-76^-
Research areas: Developmental Biology Research, Immunology, Inflammation and Autoimmunity Research

Description

These Lcp2 knockout mice exhibit a complete loss of T cells and γδ-TCR⁺ lymphocytes, but maintain a normal number of B cells, macrophages, neutrophils, mast cells and NK cells. They may be useful for studies related to T cell development.

Detailed description

SLP-76 is an immune cell adaptor expressed in T lymphocytes, macrophages, mast cells, platelets, neutrophils, and natural killer (NK) cells. It has been shown to play a role in lymphatic vascular development, T cell receptor (TCR) signaling, as well as signaling through receptors that use tyrosine base activation motifs in platelet, mast cells, neutrophils and NK cells. In these lymphocyte cytosolic protein 2 (Lcp2) knockout mice, a neomycin resistance cassette in reverse orientation disrupts the gene and abolishes Lcp2 expression. These mice have small lymph nodes and enlarged spleens when compared to controls. They exhibit a complete loss of T cells and γδ-TCR⁺ lymphocytes, but maintain a normal number of B cells, macrophages, neutrophils, mast cells and NK cells. Some homozygotes may be viable, but are born at a frequency lower than typical Mendelian ratios would predict. Substantial perinatal lethality is observed.

Development

A targeting vector was designed to replace 360 bp including exon 1 and the translational start site of the lymphocyte cytosolic protein 2 (Lcp2) gene with a neomycin resistance (neo) cassette in reverse orientation to the gene. The construct was electroporated into (129X1/SvJ x 129S1/Sv)F1-Kitl⁺-derived R1 embryonic stem (ES) cells. Correctly targeted ES cells were injected into C57BL/6J blastocysts and the resulting chimeric males were bred to C57BL/6J females. The donating investigator reports that these mice were backcrossed for at least 10 generations to C57BL/6J mice (see SNP note below). Upon arrival at The Jackson Laboratory, mice were bred to C57BL/6J (Stock No. 000664) for at least one generation to establish the colony.

A 32 SNP (single nucleotide polymorphism) panel analysis, with 27 markers covering all 19 chromosomes and the X chromosome, as well as 5 markers that distinguish between the C57BL/6J and C57BL/6N substrains, was performed on the rederived living colony at The Jackson Laboratory Repository. While the 27 markers throughout the genome suggested a C57BL/6 genetic background, 3 of 5 markers that determine C57BL/6J from C57BL/6N were found to be segregating. These data suggest the mice sent to The Jackson Laboratory Repository were on a mixed C57BL/6J ; C57BL/6N genetic background.

Allele

Symbol: Lcp2^tm1Gak
Name: targeted mutation 1, Gary A Koretzky
MGI accession ID: MGI:2180002
Generation method: Targeted
Attributes: Null/Knockout
Marker symbol: Lcp2
Marker name: lymphocyte cytosolic protein 2
Chromosome: 11
Strain of origin: (129X1/SvJ x 129S1/Sv)F1-Kitl⁺
Molecular note: Approximately 360 bp of the gene, including part of exon 1 and the translation initiation site, was replaced with a neo cassette via homologous recombination. RT-PCR analysis of homozygous mutant animals verified the absence of gene expression. Western blot and immunohistochemistry of spleen from homozygous mutant animals did not detect protein product.