Gene expression microarrays mRNA transcripts

Key Words Adrenergic function gene expression gene profiling microarray mRNA receptor transcription. 

Indistinctly of how gene expression microarrays have been produced, the goal of this type of microarray is to capture the expressed mRNA in a given sample, to rely on the identity of the expressed genes (exon, transcript, etc.), and to indirectly quantify their expression. To do this, two main approaches have been used two-channel and one-channel microarrays. 

Owing to the increasing availability of complete genome sequences, the analysis of transcription by DNA microarrays has managed to achieve an almost genomic scale measurement of mRNA levels. DNA microarrays were initially developed to quantify relative gene expression at the transcriptional level, that is, mRNA. The approach has then been extended to the analysis of single nucleotide polymorphisms (SNP) in DNA... 

The methods used for the evaluation of regulation of gene expression are too numerous to be described in detail here. They include Northern analysis to determine levels of a particular mRNA, nuclear run on to determine whether an increase in mRNA is due to an increase in the rate of transcription, and promoter deletion analysis to identify specific elements in the promoter region responsible for the control of expression. Of much current interest is the use of microarrays that permit the study of the expression of hundreds to thousands of genes at the same time. Reverse transcriptase-polymerase chain reaction and RNase protection assay techniques are used to amplify and quantitate mRNAs, while the electrophoretic mobility shift assay is used to measure binding of a transcription factor to its specific DNA consensus sequence. 

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