Chromosome 13 from A/J has replaced the homologous chromosome of C57BL/6J in this strain of the set of consomic strains with C57BL/6J as background.Read More +
The C57BL/6J background strain is homozygous for the age related hearing loss mutation Cdh23ahl, which on this background causes progressive hearing loss with onset after 10 months of age.
A chromosome substitution or consomic strain is an inbred strain with one of its chromosomes replaced by the homologous chromosome of another inbred strain. The C57BL/6J and A/J strains in this set were chosen because they differ in their susceptibility to diseases such as arthritis, asthma, atherosclerosis, cancer, several infectious diseases, inflammatory responses, and physiological, behavioral and sensory phenotypes. Chromosome substitution strain nomenclature is designated as Host Strain - Chromosome #<Donor Strain>/Laboratory code. For example, C57BL/6J-Chr1A/NaJ carries chromosome 1 for strain A/J (A) on a C57BL/6J background, was constructed in the laboratory of Joseph Nadeau (Na) and is maintained at The Jackson Laboratory (J). Chromosome substitution strains or consomic strains can accelerate quantitative trait loci identification and mapping.
Dr. Joseph Nadeau from Case Western Reserve University developed the C57BL/6J-Chr #A/NaJ strain set by replacing individual chromosomes from the A/J donor strain into the C57BL/6J host strain using a marker-assisted series of backcrosses (Nadeau et al., 2000). The set was donated to The Jackson Laboratory in 2004.
|Allele Name||age related hearing loss 1|
|Allele Synonym(s)||Cdh23753A; mdfw|
|Gene Symbol and Name||Cdh23, cadherin 23 (otocadherin)|
|Strain of Origin||multiple strains|
|Molecular Note||Genetic complementation tests have shown allelism between the mdfw (modifier of deaf waddler) locus and the ahl locus. Further analysis has shown this is caused by a G to A transition at coding nucleotide position 753 of Cdh23 (SNP rs257098870). This hypomorphic allele changes splice donor site G-GT to A-GT, causing frame skipping of exon 7. This is predicted to delete part of the 2nd and 3rd ectodomains and cause reduced message stability. Twenty-seven strains classified with ahl and carrying the 753A allele include: CD-1, RBF/DnJ, PL/J, AKR/J, RF/J, BALB/cBy, A/WySnJ, P/J, SENCARA/PtJ, DBA/1J, ALS/LtJ, C58/J, C57BLKS/J, 129P1/ReJ, C57BR/cd, SKH2/J, BUB/Bn, MA/MyJ, LP/J, 129X1/SvJ, NOR/LtJ, A/J, C57BL/6, NOD/LtJ, DBA/2J, ALR/LtJ, C57L/J. Strains classified with ahl that DO NOT carry this mutation include: 129S1/SvImJ, C3H/HeSnJ, I/LnJ, YBR/Ei, MRL/MpJ.|