Survey of microarray technologies suitable to elucidate transcriptional networks as exemplified by studying KRAB zinc finger gene families.

Current microarray systems are suitable to monitor genome-wide expression patterns, to detect single-nucleotide polymorphisms (SNP), to identify target genes of transcription factors and DNA-protein interaction sites thereof as well as to determine genomic sites that are modified by methylation of CpG islands. In this review, advantages and limitations of individual microarray technologies are presented as well as experiences from ongoing studies on KRAB zinc finger gene families are taken to exemplify how different microarray approaches are applicable to elucidate complex transcriptional networks of gene regulation. However, bioinformaticians should be aware that each microarray technology has limitations in its sensitivity and selectivity that has to be taken into account once data mining on comprehensive genome-wide microarray data is conducted. In many cases, microarray results are the initial step to identify target genes of interest and to study the molecular regulation of biological processes thereof followed and validated by complementary proteome, metabolome or toponome analysis. Thus, microarray technologies can be considered a reliable approach for determining gene functions that might be modulated by electromagnetic fields.