Ccr9-/- mice may be useful for studying the role of CCR9 in T lymphocyte development and migration.
Joshua M. Farber, National Institutes of Health
Ccr9-/- mice have a neo cassette replacing most of the coding region of the chemokine (C-C motif) receptor 9 (Ccr9), abolishing gene expression. CCR9 is a chemokine receptor that is expressed on the majority of immature CD4+CD8+ double-positive (DP) thymocytes and is down-regulated during their transition to the CD4+ or CD8+ single-positive (SP) stage. CCR9 acts by mediating T cell recruitment in response to the chemokine CCL25 and by mediating thymocyte selection within the thymus. Homozygous Ccr9-/- mice are viable and fertile. CCR9 mRNA was undetectable in the thymus, spleen, lymph node, and small intestine from these mice. αβ-B cell development, αβ-T cell development, and thymocyte selection are normal in these mice. A two fold increase in the number of γδ-T cells in the spleen and lymph nodes is evident, as is a decrease in the percentage of CD8αβ+ αβTCR+ and γδTCR+ intraepithelial lymphocytes in the small intestine.
A targeting vector was designed to replace most of exon 4, containing the coding region of the chemokine (C-C motif) receptor 9 (Ccr9) gene, with a neomycin resistance (neo) cassette. The construct was electroporated into 129-derived embryonic stem (ES) cells. Correctly targeted ES cells were injected into C57BL/6 blastocysts and the resulting chimeric males were bred to C57BL/6NCrl females. Ccr9-/- mice were bred to C57BL/6NCrl inbred mice for at least 5 generations using a speed congenic protocol. Upon arrival at The Jackson Laboratory, mice were bred to C57BL/6NJ (Stock No. 005304) for at least one generation to establish the colony.
|Allele Name||targeted mutation 1, Paul E Love|
|Allele Type||Targeted (Null/Knockout)|
|Gene Symbol and Name||Ccr9, chemokine (C-C motif) receptor 9|
|Strain of Origin||129|
|Molecular Note||A neomycin resistance gene replaced part of exon 4. Exon 4 contains most of the coding sequence. Transcript was undetectable in mutant thymus, spleen, lymph node and small intestine.|
When maintaining a live colony, homozygous mice may be bred together.
When using the CCR9 KO mouse strain in a publication, please cite the originating article(s) and include JAX stock #027041 in your Materials and Methods section.