Motr1^AKR/J
QTL Variant Detail

Summary

• QTL variant: Motr1^AKR/J
• Name: modifier of tubby retinal degeneration 1; AKR/J
• MGI ID: MGI:3056349
• QTL: Motr1 Location: Chr11:87691198-103274115 bp Genetic Position: Chr11, Syntenic

Variant origin

• Strain of Specimen: AKR/J

Variant description

• Allele Type: QTL
• Mutation: Undefined
• This allele confers resistance to retinal degeneration compared to C57BL/6J. (J:77760)
• Inheritance: Recessive

Expression

In Structures Affected by this Mutation:

2 anatomical structure(s)

Notes

This allele protects against retinal degeneration in the presence of the tubby (Tub^tub) mutation.

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

J:77760

Genome scan was performed on 106 (C57BL/6/J-Tub^tub x AKR/J)F2 intercross animals homozygous for the tubby mutation to identify QTL modifiers of tubby related retinal degeneration. 62 SSLP markers at an average spacing of 35 cM were used in the genome scan.

Significant linkage to retinal degeneration was identified at a 30 cM interval on mouse Chromosome 11. This locus is named Motr1 (modifier of tubby retinal degeneration 1) and the 95% confidence interval of Motr1 spans 38.2 cM - 68.3 cM between D11Mit39 and D11Mit360. The Motr1 locus shows linkage to outer nuclear layer (ONL) thickness with a peak LOD score of 4.3 and linkage to photoreceptor cell number (PCN) with a peak LOD score of 5.1. The AKR/J-derived allele appears to protect against retinalcell degeneration with a recessive mode of inheritance. Motr1 may explain up to 13% of the genetic variance for ONL thickness and up to 16% of the genetic variance for PCN. Candidate genes mapping within the Motr1 interval are Myo1c (44.13 cM), Myo1d (46cM), and Ngfr (55.6 cM). A previously identified QTL associated with retinal neuron number, Nnc1, maps within the Motr1 interval at 57 cM.

A suggestive modifier locus mapped to 56.8 cM on mouse Chromosome 2 near D2Mit17. Peak linkage to ONLthicknessreached LOD=2.84 and peak linkage to PCN reached LOD=2.69. The 95% confidence interval for this locus spans 34.4 cM - 77.2 cM. The AKR/J-derived allele appears to protect against retinal degeneration with a dominant mode of inheritance. This locus explains 10%of the genetic variance for ONL thickness and 9% of the genetic variance for PCN. Mtap1a, the modifier of tubby hearing (previously Moth1), maps within this interval.

A suggestive modifier locus mapped to 47 cM on mouse Chromosome 8 nearD8Mit242. Peak linkage to ONL thickness reached LOD=3.1 and peak linkage to PCN reached LOD=2.26. The 95% confidence interval for this locus spans 21.9 cM - 66.9 cM. The AKR/J-derived allele appears to enhance retinal degeneration with a dominant mode ofinheritance. Thislocus explains 10% of the genetic variance for ONL thickness and 7% of the genetic variance for PCN.

References

• Original: J:77760 Ikeda A, et al., Genetic modification of retinal degeneration in tubby mice. Exp Eye Res. 2002 Apr;74(4):455-61
• All: 1 reference(s)