Karolinska Institute, Department of Woman and Child Health, Division of Reproductive Endocrinology, Karolinska University Hospital, Building L5, 17176 Stockholm, Sweden. Sten.Cekan@kbh.ki.se
This review deals with the methods of identifying genes that have been activated by inner or outer impulses. The activation and subsequent expression of a gene can be detected by its transcription into a corresponding messenger ribonucleic acid (mRNA). Principles of the methods for identification of individual activated genes, as well as groups of activated genes are described, the former methods being mostly based on subtractive hybridization and serial analysis of gene expression (SAGE), the latter on microarrays. Examples of gene activation by the hormone 17beta-estradiol (E2) are given.