NOD.B10 Cox-2flox Line C mice develop age-related Sjogren's syndrome xerostomia and sialadenitis, and are phenotypically indistinguishable from NOD.B10Sn-H2b/J mice. Cox-2 function may be deleted when Cre recombinase is introduced.
Harvey R Herschman, University of California, Los Angeles
Patricia K.A. Mongini, The Feinstein Institute for Medical Research, North Shore-Long Island Jewish Health System
Sjogren's syndrome (SS) in humans is an autoimmune disorder characterized by salivary gland leukocytic infiltrates and hyposalivation (xerostomia), defective lachrymal gland function, multiple systemic effects, and a relatively high incidence of B cell lymphoma. In human SS, affected salivary glands show leukocytic infiltrates characterized by prominent T cell and B cell foci, occasional germinal centers, and autoantibody producing plasma cells. Cox-2 (Ptgs2; cyclooxygenase-2) converts arachidonic acid to prostaglandin H2, which is subsequently converted to several different molecules including prostaglandin E2 (PGE2). Cox-2 and downstream PGE2 are associated with regulating the production of class-switched antibodies and Th17 inflammatory cell expansion. In addition, cycling B lymphocytes show elevated synthesis of several PGE2 axis proteins as well as PGE2. Cox-2 is located within the autoimmune exocrinopathy 2 quantitative trait locus (Aec2 QTL) on chromosome 1.
Homozygous (NOD.B10 Cox-2flox/flox Line C) and heterozygous (NOD.B10 Cox-2flox Line C) mice develop age-related Sjogren's syndrome xerostomia and sialadenitis, and are phenotypically indistinguishable from NOD.B10Sn-H2b/J mice. Line C retains the NOD disease-susceptibility alleles in the ~155.8-157.36 Mbp region of the Aec2 QTL. In these mice, the 129S4-derived region around the Cox-2flox targeted mutation spans from ~144.18 Mbp to ~155.80 Mbp. Homozygous mice are viable and fertile. The donating investigator reports mice can exhibit nervous behavior and may benefit from a quieter vivarium. They also report some (not all) breeders decline in fecundity after 1-2 litters, and replacing breeding units at 3-4 months of age may improve overall colony performance.
The pCox-2-floxneo targeting vector was designed by Dr. Harvey R. Herschman (University of California, Los Angeles) to place a loxP site upstream of exon 4 and a loxP-flanked PGK-Neo cassette downstream of exon 5 of the prostaglandin-endoperoxide synthase 2 gene (Ptgs2; cyclooxygenase-2 or Cox-2) on chromosome 1 (~150.1 Mbp). This construct was electroporated into 129S4/SvJae-derived LW1 embryonic stem (ES) cells. Correctly targeted ES cells were then transiently transfected with a Cre recombinase-expressing plasmid. The resulting ES cells with the Cox-2flox genotype (neo selection cassette removed; leaving a single loxP site upstream of exon 4 and a single loxP site downstream of exon 5) were injected into recipient blastocysts. Cox-2flox mice on a mixed 129/B6 background were obtained by Dr. Patricia K.A. Mongini (The Feinstein Institute for Medical Research, North Shore-Long Island Jewish Health System). There, the mice were backcrossed to the Sjogren's syndrome-susceptible strain NOD.B10Sn-H2b/J using a marker-assisted, speed congenic approach. Specifically, Cox-2flox/+ males were crossed with NOD.B10 females to create the F1 generation. F1 females were crossed with male NOD.B10 mice to fix the Y chromosome to NOD/ShiLt. Thereafter, seven backcrossings were performed by breeding female NOD.B10 with Cox-2flox/+ males that were selected to have the greatest homology to NOD.B10 across all autosomal chromosomes and the NOD.B10 MHC type (NOD/Lt MHC alleles except for the H2b haplotype from C57BL/10SnJ). The resulting congenic line, called NOD.B10 Cox-2flox Line C, retained the NOD disease-susceptibility alleles in the ~155.8-157.36 Mbp region of the autoimmune exocrinopathy 2 (Aec2) QTL on chromosome 1. The 129S4-derived region around the Cox-2flox targeted mutation spans from ~144.18 Mbp to ~155.80 Mbp. In 2014, Dr. Mongini sent NOD.B10 Cox-2flox/flox Line C females and males to the The Jackson Laboratory Repository node of the Mutant Mouse Regional Resource Centers (MMRRC-JAX).Upon arrival, homozygous animals were bred together to maintain the live colony.
|Allele Name||b variant|
|Allele Type||Not Applicable|
|Gene Symbol and Name||H2, histocompatibility-2, MHC|
|Strain of Origin||Not Applicable|
|General Note||The b variant has been observed in the following strains: C57BL/10, C57BL/10SnJ, BXSB/MpJ, C57BL/6J, C57L/J, LP/J, 129P3/J, 129P1/ReJ.|
|Allele Name||targeted mutation 1, Harvey R Herschman|
|Allele Type||Targeted (Conditional ready (e.g. floxed), No functional change)|
|Allele Synonym(s)||Cox-2flox; Ptgs2tm1Hrh|
|Gene Symbol and Name||Ptgs2, prostaglandin-endoperoxide synthase 2|
|Strain of Origin||129S4/SvJae|
|Molecular Note||A targeting vector was designed to flank exons 4 and 5 with loxP sites. Deletion of these exons would cause a frame shift, resulting in a stop codon after eight missense amino acids in exon 6.|
When maintaining a live colony, homozygous mice may be bred together. The donating investigator reports mice can exhibit nervous behavior and may benefit from a quieter vivarium. They also report some (not all) breeders decline in fecundity after 1-2 litters, and replacing breeding units at 3-4 months of age may improve overall colony performance.
When using the Cox-2flox mouse strain in a publication, please cite the originating article(s) and include MMRRC stock #37505 in your Materials and Methods section.