Liver expression of B6.C3H-6T (6T) (congenic mice with low serum IGF-1) and C57BL/6J mice
Several studies have shown that bone mineral density (BMD), a clinically measurable predictor of osteoporotic fracture, is the sum of genetic and environmental influences. In addition, serum IGF-1 levels have been correlated to both BMD and fracture risk. We previously identified a Quantitative Trait Locus (QTL) for Bone Mineral Density (BMD) on mouse Chromosome (Chr) 6 that overlaps a QTL for serum IGF-1. The B6.C3H-6T (6T) congenic mouse is homozygous for C57BL/6J (B6) alleles across the genome except for a 30 cM region on Chr 6 that is homozygous for C3H/HeJ (C3H) alleles. This mouse was created to study biology behind both the BMD and the serum IGF-1 QTLs and to identify the gene(s) underlying these QTLs. Female 6T mice have lower BMD and lower serum IGF-1 levels at all ages measured. As the liver is the major source of serum IGF-1, we examined differential expression in the livers of fasted female B6 and 6T mice by microarray. The experimental design of this experiment was a simple two-factor experiment, with three biological replicates of each factor (in this case mouse strain, B6.C3H-6T vs. C57BL/6J). Each sample represented one mouse; no samples were pooled. No technical replicates were done. Platform Affymetrix GeneChip Mouse Genome 430 2.0 Array.
PPARG by dietary fat interaction influences bone mass in mice and humans
Ackert-Bicknell CL, Demissie S, Marín de Evsikova C, Hsu YH, DeMambro VE, Karasik D, Cupples LA, Ordovas JM, Tucker KL, Cho K, Canalis E, Paigen B, Churchill GA, Forejt J, Beamer WG, Ferrari S, Bouxsein ML, Kiel DP, Rosen CJ.
J Bone Miner Res. 2008 Sep;23(9):1398-408. PMCID: PMC2683155 [ Full Text ]