Fbrwt1^DBA/2J
QTL Variant Detail

Summary

• QTL variant: Fbrwt1^DBA/2J
• Name: forebrain weight 1; DBA/2J
• MGI ID: MGI:3834643
• QTL: Fbrwt1 Location: unknown Genetic Position: Chr1, Syntenic

Variant origin

• Strain of Specimen: DBA/2J

Variant description

• Allele Type: QTL

Notes

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

J:143361

Linkage analysis was performed on 34 BXD/TyJ (B=C57BL/6J; D=DBA/2J) recombinant inbred (RI) strains to identify genetic loci associated with forebrain weight. Approximately 11 mice from each BXD/TyJ line were phenotyped at an average age of 82 days usinga panel of 3795 polymorphic markers. A series of filters was then used to identify candidate genes based on proximity to the QTL, mRNA and protein expression differences between BXD/TyJ RI lines and parental strains C57BL/6J and DBA/2J, and coding sequence variation.

Significant linkage (P>0.05) to mouse forebrain weight mapped to mouse Chromosome 1 between 114 Mb and 162 Mb and is named Fbrwt1 (forebrain weight 1). C57BL/6J-derived alleles at Fbrwt1 confer increased forebrain weight. Positional and microarray analysis identified Tnni1 at 137.67 Mb as a potential candidate gene for Fbrwt1. Tnni1 displays 3-fold increased expression in BXD/TyJ RI lines carrying the C57BL/6J allele at this locus (cis-eQTL LRS=25.2). Tnni1 is typically expressed inskeletal muscle but is present in the mouse brain as well. A 273 indel was detected upstream of the Tnni1 transcription start site but its significance is unclear at the present time.

Significant linkage (P>0.05) to mouse forebrain weight mapped to mouse Chromosome 11 between 0 Mb and 42 Mb and is named Fbrwt2 (forebrain weight 2). C57BL/6J-derived alleles at Fbrwt2 confer increased forebrain weight. Asb3 at 30.85 Mb was identified as a potential candidate gene for Fbrwt2 and is highly expressed in brain tissue. A 2-fold increase in mRNA expression is present in BXD/TyJ RI animals carrying the C57BL/6J allele at Asb3 (cis-eQTL LRS=36.1). In addition, 2.3-fold increased Asb3 protein expression in forebrain tissue was observed in BXD25, one of the high mRNA expressing lines. Brwt3 at 16cM and Brnvl1 at 13 cM are previously identified brain weight QTLs located near Fbrwt2.

References

• Original: J:143361 Lu L, et al., Using gene expression databases for classical trait QTL candidate gene discovery in the BXD recombinant inbred genetic reference population: mouse forebrain weight. BMC Genomics. 2008;9:444
• All: 1 reference(s)