Map1a^Moth1-r
QTL Variant Detail

Summary

• QTL variant: Map1a^Moth1-r
• Name: microtubule-associated protein 1 A; modifier of tubby hearing 1, resistant
• MGI ID: MGI:2154969
• Synonyms: moth^129/Ola
• QTL: Map1a Location: Chr2:121120081-121141313 bp, + strand Genetic Position: Chr2, 60.37 cM

Variant origin

• Strain of Specimen: multiple strains

Variant description

• Allele Type: QTL
• Mutation: Not Applicable
• Mutation details: The presence of AKR/J, Cast/Ei, or 129P2/OlaHsd alleles protect tubby mice from hearing loss, while the C57BL/6 allele renders tubby mice susceptible to hearing loss. Numerous sequence polymorphisms in Mtap1a were observed between the susceptible and resistant strains. Verification of Mtap1a as the gene responsible for the moth1 phenotype was achieved by transgenic rescue. (J:75815)
• Inheritance: Dominant

Notes

Mapping and Phenotype information for this QTL, its variants and associated markers

J:111838

Linkage analysis was performed in 144 (C3HeB/FvJ-Tmc1^Bth x C57BL/6J)F1 x C57BL/6J and 180 (C3HeB/FvJ-Tmc1^Bth x DBA/2J)F1 x DBA/2J backcross animals to identify modifiers of the Tmc1^Bth Beethoven mutation. Parental strain C3HeB/FeJ-Tmc1^Bth exhibits deafness by 3 weeks of age, near complete inner hair cell degeneration, and graduated outer hair cell degeneration. Genome scan was performed with polymorphic markers spaced 20 cM apart. Hearing loss was evaluated by distortion product otoacoustic emission (DPOAE) analysis.

A modifier of Tmc1 mapped to 46 cM on mouse Chromosome 2 with LOD=5.8 near D2Mit37. The QTL interval spans 39 cM (D2Mit92) to 75 cM (D2Mit224). This locus explains 16% of the variance and is designated Tmc1m1 (Tmc1 modifier 1). C57BL/6J-derived alleles at Tmc1m1 confer susceptibility to Tcm1^Bth-associated hearing loss (decreased DPOEA amplitudes). Potential candidate genes for Tmc1m1 include Tmc2 and Mtap1a (67.5 cM).

Tmc1m2 (Tmc1 modifier 2) mapped to 55 cM on mouse Chromosome 11 with LOD=8.5 near D11Mit70. This locus explains 19% of the variance. The QTL interval spans 33 cM (D11Mit164) to 63 cM (D11Mit253). DBA/2J-derived alleles at Tmc1m2 confer susceptibility to Tcm1^Bth-associated hearing loss (decreased DPOEA amplitudes).Myo1c at 44.13 cM is a potential candidate gene for Tmc1m2.

Tmc1m3 (Tmc1 modifier 3) mapped to 3 cM on mouse Chromosome 12 with LOD=4.3 near D12Mit37. The QTL interval spans 1 cM (D12Mit37) to 32 cM (D12Mit52). This locus explains 10% of the variance. DBA/2J-derived alleles at Tmc1m3 confer susceptibility to Tmc1^Bth-associated hearing loss (decreased DPOEA amplitudes).

Tmc1m4 (Tmc1 modifier 4) mapped to 61 cM on mouse Chromosome 5 with LOD=3.6 near D5Mit158. The QTL interval spans 40 cM (D5Mit394) to69 cM (D5Mit161). This locus explains 9% of the variance. DBA/2J-derived alleles at Tmc1m4 confer susceptibility to Tmc1^Bth-associated hearing loss (decreased DPOEA amplitudes). Previously identified hearing loss QTL Ahl2 at 44 cM overlaps with Tmc1m4.

Suggestive linkage to Tmc1-^Bth hearing loss mapped to 60 cM (D15Mit147, LOD=2.8) on mouse Chromosome 15 and 25 cM (D17Mit51, LOD=2.7) on mouse Chromosome 17. C57BL/6J-derived alleles confer decreased hearing loss at both loci.

References

• Original: J:57571 Ikeda A, et al., Genetic modification of hearing in tubby mice: evidence for the existence of a major gene (moth1) which protects tubby mice from hearing loss. Hum Mol Genet. 1999 Sep;8(9):1761-7
• All: 3 reference(s)