title: To What Extent is Blood a Reasonable Surrogate for Brain in Gene Expression Studies: Estimation from Mouse Hippocampus and Spleen.
abstract: Microarrays are designed to measure genome-wide differences in gene expression. In cases where a tissue is not accessible for analysis (e.g. human brain), it is of interest to determine whether a second, accessible tissue could be used as a surrogate for transcription profiling. Surrogacy has applications in the study of behavioural and neurodegenerative disorders. Comparison between hippocampus and spleen mRNA obtained from a mouse recombinant inbred panel indicates a high degree of correlation between the tissues for genes that display a high heritability of expression level. This correlation is not limited to apparent expression differences caused by sequence polymorphisms in the target sequences and includes both cis and trans genetic effects. A tissue such as blood could therefore give surrogate information on expression in brain for a subset of genes, in particular those co-expressed between the two tissues, which have heritably varying expression.
authors.affiliation: Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, King's College London London, UK.
authors.forename: Matthew N
authors.initials: MN
authors.lastname: Davies
authors.forename: Sarah
authors.initials: S
authors.lastname: Lawn
authors.forename: Steven
authors.initials: S
authors.lastname: Whatley
authors.forename: Cathy
authors.initials: C
authors.lastname: Fernandes
authors.forename: Robert W
authors.initials: RW
authors.lastname: Williams
authors.forename: Leonard C
authors.initials: LC
authors.lastname: Schalkwyk