Transcription profiling of rat femur to identify segregation of skeletal phenotypes in congenic P/NP rats
ABSTRACT: Bone mineral density and structure candidate gene analysis in alcohol-non-preferring (NP), alcohol-preferring (P), congenic NP (NP.P) and congenic P (P.NP) rats; Genetic mapping in alcohol-preferring (P) and alcohol-non-preferring (NP) rats has identified a major quantitative trait locus (QTL) in the region between q22 – q34 on chromosome (Chr) 4 for alcohol preference. In a separate genome-wide linkage study, using inbred Fischer 344 (F344) and Lewis (LEW) rats, several QTL linked to bone density and structure were identified at the same location suggesting that bone mass and strength genes might co-segregate with genes that regulate the alcohol preference trait. The aim of this study is to identify the genes segregating for skeletal phenotypes and alcohol trait in congenic P/NP rats. We compared bone mineral content (BMC), areal/volumetric bone mineral density (aBMD/vBMD) and biomechanical strength at different skeletal sites from 6-month-old inbred and congenic P/NP rats. Transfer of the NP Chr 4 QTL into P background significantly increased body weight but decreased BMC, aBMD/vBMD in whole body, cranium, femur, and lumbar vertebrae. On the other hand, transfer of P Chr 4 QTL into NP background significantly decreased body weight but increased BMC and aBMD in the same skeletal sites. Microarray analysis was performed from the femurs of 4-week-old rats (n = 5 per strain) using Affymetrix Rat Genome 230 2.0 arrays. A total of 53 genes, including 41 candidate genes and 12 predicted genes, were differentially expressed among all strains of rats with a false discovery rate (FDR) less than 10%. Several candidate genes from microarray analysis were found to be were strongly correlated (r2>0.50) with different skeletal phenotypes. Gene expression of top 3 candidate genes from microarray profiling was validated by quantitative real-time PCR (qRT-PCR). Ingenuity pathway analysis revealed relationships among the candidate genes related to bone metabolism including pathways related to beta-estradiol, tumor necrosis factor and androgen receptor. Experiment Overall Design: Comparison of differentially expressed genes between 4q22-4q34 on chromosome 4 in NP, P, NP.P and P.NP rats.
INSTRUMENT(S): 418 [Affymetrix]
ORGANISM(S): Rattus Norvegicus
SUBMITTER: Charles Turner
PROVIDER: E-GEOD-12066 | ArrayExpress | 2009-07-11
SECONDARY ACCESSION(S): GSE12066PRJNA113401
REPOSITORIES: GEO, ArrayExpress