Aaj2^C57BL/6J
QTL Variant Detail

Summary

• QTL variant: Aaj2^C57BL/6J
• Name: anxiety in A/J 2; C57BL/6J
• MGI ID: MGI:3573911
• QTL: Aaj2 Location: Chr6:4503823-48703611 bp Genetic Position: Chr6, Syntenic

Variant origin

• Strain of Specimen: C57BL/6J

Variant description

• Allele Type: QTL
• Inheritance: Dominant

Notes

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

J:96389

A panel of chromosome substitution strains (CSS) was used to map QTLs associated with anxiety and emotionality. The CSSs were derived from A/J donor chromosomes on a C57BL/6J genetic background. Background strain C57BL/6J exhibits low anxiety/emotionality as these animals spend more time in lighted areas in the light dark test, traverse greater distances in the open field, and display decreased open field defecation compared to donor strain A/J.

The CSS strain for chromosome 1 exhibits decreased activity in the open field test and light dark test so this strain was selected for further study. A backcross was constructed between the CSS and C57BL/6J. 91 animals from a (C57BL/6J-Chr1^A/J x C57BL/6J)F1 x C57BL/6J backcross were screened for markers on chromosome 1 at an average resolution of 15-20 cM. A QTL interval spanning approximately 65 cM - 110 cM between D1Mit151 to D1Mit511 was identified. Linkage to time to first emergence in the light dark test mapped to 93 cM with LOD=3.3, and linkage to total time spent in light chamber mapped to 103 cM with LOD=4.1. Linkage to open field defecation was detected at 95.5 cM with LOD=6.7, and weak linkage to open field activity was detected at 113 cM with LOD=0.96. Combined and averaged phenotypes gave a LOD score of 1.9 near 81.6 cM, which is considered significant. This QTL is near the location of the previously identified anxiety QTLs Axtofa1 (74 cM) and Emo3 (73 cM) and may represent the same locus. This locus is designated Aaj1 (anxiety in A/J 1) until further studies prove or disprove its identity to Axtofa1 and/or Emo3. A QTL identified by another group named Exq2 at 70 cM also maps near Aaj1.

The chromosome 6 CSS displayed decreased activity in the open field test so linkage analysis was performed for this strain. 82 animals from a (C57BL/6J-Chr6^A/J x C57BL/6J)F2 intercross were screened for markers on chromosome 6 at an average resolution of 15-20 cM. Linkage to decreased open field activity was detected at 4.9 cM with LOD=3.7 between D6Mit138 and D6Mit274. This QTL is designated Aaj2 (anxiety in A/J 2). Aaj2 spans approximately 0 cM - 20 cM, and also shows linkage to open field defecation (LOD=1.7 at 17 cM) and suggestive linkage to light dark test traits (LOD=1.1-1.5 at 2.1 cM). A second QTL was detected at 52.5 cM with LOD=1.6 between D6Mit36 and D6Mit339 and is considered statistically significant. This locus is designated Aaj3 (anxiety in A/J 3). Aaj3 also shows suggestive linkage to light dark traits. A/J-derived alleles confer decrease open field activity at Aaj2 and Aaj3 with a recessive mode of inheritance.

Linkage analysis was performed on the chromosome 17 CSS to identify QTLs for light dark test traits. 70 animals from a (C57BL/6J-Chr17^A/J x C57BL/6J)F2 intercross were screened for chromosome 17 markers at an average resolution of 15-20 cM. Linkage to total time spent in the light was detected at 51.2 cM with LOD=3.6 between D17Mit39 and D17Mit221. This QTL is designated Aaj4 (anxiety in A/J 4). A/J-derived alleles at Aaj4 confer decreased total time spent in the lighted area.

References

• Original: J:96389 Singer JB, et al., Mapping quantitative trait Loci for anxiety in chromosome substitution strains of mice. Genetics. 2005 Feb;169(2):855-62
• All: 1 reference(s)