B6.129P2(C)-Ptprj^tm1.2Weis/J

Stock number: 008289
Research areas: Immunology, Inflammation and Autoimmunity Research, Reproductive Biology Research

Description

Gene targeting was used to remove a transmembrane domain from the targeted protein. Homozygotes exhibit a partial peripheral B cell development block at the first transitional stage (T1), although total T or B cell numbers in the spleen and lymph node are unchanged. Truncated product (mRNA) is detected by Northern blot analysis of splenocytes isolated from homozygous animals. A secreted protein without known physiologic consequences is detected in serum from homozygous animals, but no surface protein is detected on cells of hematopoietic lineage, including T cells, B cells, and myeloid cells. This strain may be useful for studies of immune responses.

Detailed description

Gene targeting was used to remove a transmembrane domain from the targeted protein. Homozygotes exhibit a partial peripheral B cell development block at the first transitional stage (T1), although total T or B cell numbers in the spleen and lymph node are unchanged. Truncated product (mRNA) is detected by Northern blot analysis of splenocytes isolated from homozygous animals. A secreted protein without known physiologic consequences is detected in serum from homozygous animals, but no surface protein is detected on cells of hematopoietic lineage, including T cells, B cells, and myeloid cells. Mice that are heterozygous for the targeted mutation are viable, fertile, normal in size and do not display any gross physical or behavioral abnormalities; homozygotes are not fertile. This strain may be useful in studies of immune responses.

Development

A targeting vector was designed to introduce a loxP-flanked neomycin (neo) resistance cassette in reverse transcriptional orientation to intron 17 and an additional loxP site to intron 18. Exon 18 encodes the transmembrane domain of the gene (also called CD148). The targeting construct was transfected into 129P2/OlaHsd-derived E14.1TG3B1 embryonic stem (ES) cells. Correctly targeted ES cells were injected into recipient blastocysts. Targeted animals were bred with BALB/c-Tg(CMV-cre)1Cgn/J female mice (Stock No. 003465) to remove the floxed sequences. The resulting offspring contained multiple gene rearrangments; intact floxed-exon 18, intact floxed-neo cassette, or excision of both exon 18 and the neo cassette. Correctly targeted progeny, lacking exon 18 and the neo cassette, were bred to remove the CMV-Cre transgene. This line was backcrossed to C57BL/6 for at least 12 generations by the donating laboratory. Upon arrival at The Jackson Laboratory, mice were bred to C57BL/6J (Stock No. 000664) for at least one generation to establish the colony.

Allele

Symbol: Ptprj^tm1.2Weis
Name: targeted mutation 1.2, Arthur Weiss
MGI accession ID: MGI:3774766
Generation method: Targeted
Attributes: Null/Knockout
Marker symbol: Ptprj
Marker name: protein tyrosine phosphatase, receptor type, J
Chromosome: 2
Strain of origin: 129P2/OlaHsd
Molecular note: A targeting vector was designed to introduce a loxP-flanked neomycin-resistance cassette in reverse transcriptional orientation to intron 17 and an additional loxP site to intron 18. Exon 18 encodes the transmembrane domain of the gene (also called CD148). Targeted animals were bred with BALB/c-background CMV-Cre transgenic female mice to delete the neomycin cassette and exon 18. Transmembrane domain-deleted mice were obtained and characterized. CD148 protein is not detected on any cells of hematopoietic origin by immunoblotting or flow cytometry.