Experiment
The distal portion of mouse Chromosome 2 was found to be linked to obesity traits in previous studies. A congenic strain was constructed which carries C57BL/6J-derived donor DNA from D2Mit306 (61.2 cM) to D2Mit52 (99 cM) on an M16i genetic background. This congenic is called M16i.B6-(D2Mit306-D2Mit52) contains the distal chromosome 2 obesity locus. Donor strain C57BL/6J is relatively lean whereas background strain M16i is obese, hyperinsulinemic, and hyperglycemic.
The M16i.B6-(D2Mit306-D2Mit52) congenic exhibits significantly decreased body weight (15% decreased compared to M16i), fatness, and plasma leptin, glucose, and insulin levels at 15 weeks of age. This reduction in body fat is not the result of decreased food intake or increased energy expenditure. The results identify a locus on distal mouse Chromosome 2, Gnf, growth and fatneess QTL, influencing obesity and energy balance.
The previously identified QTLs mapping to the congenic region are Scfq1 (84 cM), Epfq1 (84 cM), Epfq2 (97.6 cM), and Epfpq2 (66.8 cM). Several genes mapping within the congenic region show differential expression between M16i and M16i.B6-(D2Mit306-D2Mit52) mice in liver and adipose tissue (see reference for details).
6.23.2015 Curator Note: Scfq1 was originally mapped in J:87793 in 2004 using an (M16i x L6)F2 cross, which differs from the cross used here. We consider this a separate map study and have named the QTL identified as the 15 week subcutaneous fat variable - Scfq5.
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