Similarity and variation in gene expression among human cerebral cortical subregions revealed by DNA macroarrays: technical consideration of RNA expression profiling from postmortem samples.
The functional regionality of the human cerebral cortex suggests that a set of genes might be activated in each subregion of the neocortex to support its specific functions. To test this hypothesis, we employed the DNA array technique to compare the mRNA expression profiles of three neocortical subregions of the human brain: prefrontal cortex (Area 46), motor cortex (Area 4) and visual cortex (Area 17). The macroarray analysis on high quality mRNA from postmortem brains revealed that the expression profiles of the different cortical areas are almost similar: only six out of 1088 known genes exhibited significant differences (>2-fold) in their expression. RT-PCR studies with an increased number of samples confirmed that expression of only two genes, annexin II and early growth response protein 1, varied by 2-fold among the regions, whereas expression of the others showed large inter-individual difference. These results suggest that the whole neocortex of humans is more homogeneous than we expected at the level of gross gene expression profiles. In parallel, sensitivity and accuracy of radioisotope-based DNA macroarrays and fluorescence-based DNA microarrays were tested.
Watakabe
A
A
National Institute for Basic Biology, Okazaki, Japan.
Sugai
T
T
Nakaya
N
N
Wakabayashi
K
K
Takahashi
H
H
Yamamori
T
T
Nawa
H
H
D000368:Aged; D017306:Annexin A2 / Q000235:genetics; D001923:Brain Chemistry / Q000235:genetics; D002540:Cerebral Cortex / Q000502:physiology*; D004268:DNA-Binding Proteins / Q000235:genetics; D051766:Early Growth Response Protein 1; D005456:Fluorescent Dyes; D015870:Gene Expression / Q000502:physiology; D006801:Humans; D017874:Immediate-Early Proteins; D008875:Middle Aged; D009044:Motor Cortex / Q000502:physiology; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods*; D017397:Prefrontal Cortex / Q000502:physiology; D012333:RNA, Messenger / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012680:Sensitivity and Specificity; D014157:Transcription Factors / Q000235:genetics; D014793:Visual Cortex / Q000502:physiology
D017306:Annexin A2; D004268:DNA-Binding Proteins; C497325:EGR1 protein, human; D051766:Early Growth Response Protein 1; D005456:Fluorescent Dyes; D017874:Immediate-Early Proteins; D012333:RNA, Messenger; D014157:Transcription Factors