Genes 2 Brains 2 Mind 2 Me

Image via Wikipedia A look at almost any gene expression pattern in the brain will most certainly confuse you. This is in contrast to functional imaging studies that often show that the brain is organized into neat, aesthetically pleasing functional circuits. Why don’t genes show similar neat expression patterns that reflect a common functional organization ? Some clues to this can be found in the recent paper, “A survey of genetic human cortical gene expression” by Myers and company (DOI). Their joint analysis of individual variation at the level of genome sequence (Affy 500K array) and mRNA-expression (Illumina Refseq-8 Expression BeadChip) shows that most of the correlations between gene sequence and gene expression are between genetic variants that are far away from the genes whose expression they are correlated with (so-called, trans, effects). The team found 433 SNP-transcript pairs (99 transcripts) that showed a significant specific empirical cis association and 16,701 SNP-transcript pairs (2,876 transcripts) that showed a significant trans association. This result is similar to a previous study using mice DOI that found that the expression of the mouse strain-specific genes was driven mainly by cis-acting regulatory elements, whereas the brain region-specific genes were mainly regulated by trans-acting regulators. Thus, it seems that a given non-coding snp variant may be more likely to influence expression outside its local (50kb) neighborhood than close by. The authors generously provide access to this important data for folks who would like to query candidate snps. Manga !