Mom21^BTBR
QTL Variant Detail

Summary

• QTL variant: Mom21^BTBR
• Name: modifier of Min 21; BTBR
• MGI ID: MGI:3723022
• QTL: Mom21 Location: Chr18:11893676-11893823 bp Genetic Position: Chr18, Syntenic

Variant origin

• Strain of Specimen: BTBR

Variant description

• Allele Type: QTL
• Mutation: Undefined
• This allele confers 3-fold increased intestinal tumor multiplicity compared to C57BL/6. (J:123865)
• Inheritance: Recessive

Notes

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

J:123865

A novel colorectal cancer susceptibility modifier named Mom7 (modifier of Min 7) mapped to proximal mouse Chromosome 18. This locus was identified by genotyping 71 markers in 162 animals from a (C57BL/6 x AKR-Pla2g2a^Mom1)F1 x AKR-Apc^MinPla2g2a^Mom1 backcross.

(The AKR-Pla2g2a^Mom1 congenic line carries C57BL/6-derived DNA from D4Mit13-D4Mit54 on an AKR genetic background.) Significant linkage (LOD=21) mapped to 1 cM (3.7 Mb) on chromosome 18 corresponding with D18Wis1 on MGSC Build 36. Mice homozygous for the AKR allele at D18Wis1 developed 3 fold smaller intestinal tumors than those heterzygous with B6 and AKR alelles at the same locus.

Mom7 was also confirmed in 90 (C57BL/6 x AKR-Pla2g2a^Mom1)F2 intercross animals. AKR-derived alleles at Mom7 confers increased small intestinal tumor multiplicity by approximately 2-fold with a recessive mode of inheritance. Mom7 appears to act independently of Pla2g2a (formerly Mom1) on chromosome 4.

Mom7 was also detected in a partial genome scan of a backcross involving BTBR- Pla2g2a^Mom1 and C57BL/6. Peak linkage mapped with marker D18Mit110 (4 cM or 11.9 Mb). BTBR-derived alleles at Mom7 confer increased small intestinal and colon tumors by 3-fold with recessive inheritance. Complementation studies of AKR- and BTBR-derived Mom7 alleles suggest they are the same locus and have the same tumor-promoting effect.

Curator Note: Because Mom7 was orginally mapped in the first mapping population cited in this study and it differs from the BTBR-Pla2g2a^Mom1 x C57BL/6J backcross cited and used above we condsider the BTBR backcross as a separate mapping expermiment and have named the QTL identified using it as Mom21, modifier of Min 21.

SNP haplotype analysis revealed that AKR, BTBR, and A/J share a 0.9 Mb haploptype block from 3.5 Mb - 4.4 Mb on chromosome 18 that is distinct from C57BL/6.

References

• Original: J:123865 Kwong LN, et al., Identification of Mom7, a novel modifier of Apc(Min/+) on mouse chromosome 18. Genetics. 2007 Jun;176(2):1237-44
• All: 1 reference(s)