eNOS- C57BLKS/J Leprdb double mutant mice harbor both the spontaneous Leprdb mutation and nitric oxide synthase 3, endothelial cell (Nos3 or eNOS) knock-out targeted mutation. Double homozygous eNOS-/- C57BLKS/J db/db mice (also called eNOS-/- db/db, or db/db/eNOS-/- double mutant mice) are a robust model of type II diabetic nephropathy and may be useful for studying eNOS-mediated events in the development and progression of diabetic nephropathy.
Dr. Raymond C. Harris, Vanderbilt University Med Center
These double mutant mice harbor both the Leprdb spontaneous mutation and the Nos3 (eNOS) targeted mutation and are congenic on C57BLKS/J genetic background. Mice homozygous for both mutations (called eNOS-/- C57BLKS/J db/db, eNOS-/- db/db, or db/db/eNOS-/- double mutant mice) are viable with development of type II diabetes and diabetic nephropathy. The eNOS-/- C57BLKS/J db/db mice develop type II diabetes with significant obesity and hypertension: while both mutations are associated with insulin resistance, the mutated leptin receptor in db/db mice chiefly accounts for the observed hyperglycemia and defective leptin signaling (leading to persistent hyperphagia and obesity), and the eNOS-deficiency accounts for the moderate systemic hypertension. In addition, eNOS-/- C57BLKS/J db/db mice exhibit rapid onset and progression of pathologic diabetic nephropathy (DN) features by 26 weeks of age; developing severe albuminuria and other DN characteristics (including arteriolar hyalinosis, increased glomerular basement membrane thickness, mesangial expansion, mesangiolysis, and focal segmental and early nodular glomerulosclerosis), also with remarkably decreased glomerular filtration rate (GFR; on the basis of impaired inulin clearance and increased serum creatinine). Double homozygous eNOS-/- C57BLKS/J db/db mice are a robust model of type II diabetic nephropathy and may be useful for studying eNOS-mediated events in the development and progression of diabetic nephropathy.
These eNOS- C57BLKS/J Leprdb double mutant mice were generated in the laboratory of Dr. Raymond C. Harris (Vanderbilt University) by backcrossing eNOS-mutant mice (Stock No. 002684) to C57BLKS/J inbred mice (Stock No. 000662) for ten generations, and then the resulting mice were bred with the BKS.Cg-Dock7m +/+ Leprdb/J repulsion stock (Stock No. 000642). Mice homozygous for the eNOS knock-out allele, heterozygous for Leprdb, and segregating for misty (m) were sent to The Jackson Laboratory. Upon arrival, mice were bred with C57BLKS/J inbred mice (Stock No. 000662) to establish this colony (and remove misty).
The diabetes allele (Leprdb) is a spontaneous mutation of the leptin receptor locus on chromosome 4. The eNOS knock-out targeted mutation allele (Nos3tm1Unc) has a neomycin cassette replacing 129 bp of exon 12 of the nitric oxide synthase 3, endothelial cell locus on chromosome 5.
In 2018, A 48 SNP (single nucleotide polymorphism) panel analysis, with 43 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. One of the 43 markers, on Chromosome 11, was segregating.
|Allele Synonym(s)||db; db/db; Lepdb; Lepr-; Leprdb-1J; leprdb|
|Gene Symbol and Name||Lepr, leptin receptor|
|Strain of Origin||C57BLKS/J|
|General Note|| |
Phenotypic Similarity to Human Syndrome: Gestational Diabetes J:219658
|Molecular Note||An intronic G-to-T transversion in this allele created a donor splice site that causes abnormal splicing and the inclusion of 106 nt of intronic sequence in the transcript, leading to premature termination of the long cellular domain of the Ob-Rb splice form and loss of its signal transducing function.|
|Allele Name||targeted mutation 1, University of North Carolina|
|Allele Type||Targeted (Null/Knockout)|
|Allele Synonym(s)||ecNOS-; eNOS-; eNOSKO; NOS3-|
|Gene Symbol and Name||Nos3, nitric oxide synthase 3, endothelial cell|
|Strain of Origin||129P2/OlaHsd|
|Molecular Note||A 1.2 kb neomycin cassette replaced 129 bp of exon 12 of the gene. This disrupted the calmodulin binding site of the protein and introduced a premature stop codon into the transcripts. Immunohistochemisty of heart and kidney sections from homozygous mutant mice confirmed that no detectable encoded protein was present.|
|Mutations Made By|| |
Dr. Oliver Smithies, University of North Carolina at Chapel Hill
When maintaining a live colony, mice heterozygous for the Leprdb spontaneous mutation and homozygous for the Nos3 (eNOS-/-) targeted mutation may be bred together. NOTE: These mice have significant breeding difficulties. Approximately 16% of Het Hom x Het Hom matings are non-productive; approximately 23% of females only produce one litter; pre-wean loss is approximately 10%; 20% of breeders are found dead prior to retirement at 6-8 months of age.
When using the eNOS-/- C57BLKS/J db mouse strain in a publication, please cite the originating article(s) and include JAX stock #008340 in your Materials and Methods section.