Welcome to mirEX
MicroRNAs are key post-transcriptional regulators of gene expression in Eukaryota. In Arabidopsis thaliana miRNA genes that encode the same miRNA species are grouped in gene families. The number of gene family members varies between 1 (miR163) to 13 (miR169 ; miRBase release 17). MicroRNA genes that belong to the same family, although identical or almost identical as mature microRNAs, differ considerably in gene organization and sequence. Northern hybridizations used for the detection of mature microRNAs do not permit evaluation of the individual gene family member expression levels.
We designed cDNA and gene-specific primers for 190 microRNA from A.thaliana genes (miRBase release 13) to simultaneously monitor pri-miRNA expression pattern of individual genes using quantitative real-time PCR. Our analyses cover the following plant developmental stages and organs: 10 day-old seedlings, 14 day-old seedlings, 25 day-old plants, 35 day-old plants, 42 day-old plants (rosette leaves and stems), 53 day-old plants (rosette leaves, stems/inflorescence/siliques), and seeds, respectively. To our knowledge mirEX is the only one database to show miRNA gene expression in dry seeds [Material and Methods].
This database aims to be useful to anyone investigating the role of microRNAs in shaping plant development, organ formation and response to different biotic and abiotic stresses. To start exploring the database just press the 'Browse Atlas' button or search for a particular microRNA record by typing at least two numbers from its ID in the window. Detailed information and available features of mirEX database interface are presented as a video-tutorial on the right.
If you make use of the data presented here, please cite the following article in addition to the primary data sources:
Bielewicz D, Dolata J, Zielezinski A, Alaba S, Szarzynska B, Szczesniak M, Jarmolowski A, Szweykowska-Kulinska Z, Karlowski WM. (2012) mirEX: a platform for comparative exploration of plant pri-miRNA expression data. Nucleic Acids Res 40: D191–7.