A new atlas of gene expression in the mouse brain provides insight into how genes work in the outer part of the brain called the cerebral cortex. In humans, the cerebral cortex is the largest part of the brain, and the region responsible for memory, sensory perception and language.
Mice and people share 90 percent of their genes so the atlas, which is based on the study of normal mice, lays a foundation for future studies of mouse models for human diseases and, eventually, the development of treatments. Researchers from the National Human Genome Research Institute (NHGRI), part of the National Institutes of Health, and from Oxford University in the United Kingdom, published a description of the new atlas in the Aug. 25, 2011, journal Neuron. The study describes the activity of more than 11,000 genes in the six layers of brain cells that make up the cerebral cortex.
"This study shows the power of genomic technologies for making unexpected discoveries about the basic biology of life," said NHGRI Director Eric D. Green, M.D., Ph.D. "The brain is our most complex organ. Until we understand how it is built and how it functions based on our genetic blueprint, we will be hampered in keeping the brain healthy or dealing with its terrible diseases."
To map gene activity in all six layers of the mouse cerebral cortex, the research team first micro-dissected the brains of eight adult mice, separating the layers of the cortex. They then purified processed RNAs, including messenger RNA, from each cortical layer.
The cell creates messenger RNA (mRNA) when genes are switched on and the DNA code is read out to make proteins. The presence of an mRNA indicates that a gene is turned on, and the amount of mRNA shows the extent to which the gene is active.
To determine which genes were turned on and to what extent, the researchers used a relatively new sequencing technology called RNA-seq. The technique depends on two st
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NIH/National Human Genome Research Institute