Table 1

Definition of terms

Conditional knockoutAn organism where gene disruption occurs in a tissue-or time-specific manner
DicerAn enzyme involved in the processing of precursor microRNAs (pre-miRNAs) into mature miRNAs
EpigeneticsAll changes in gene function that can be transmitted from one generation to the next, but that are not coded in the DNA sequence itself. Examples are DNA methylation or histone acetylation
Gene promoterA region of DNA where transcription of genes is initiated
Gene set enrichment analysisA computational method used to determine whether an a priori defined set of genes shows statistically significant differences between two biological states
HypermethylationHigh degree of DNA methylation, resulting in a decreased gene expression
IntronsNucleotide sequences within a transcribed gene that are removed (spliced out) when the mature RNA product of a gene is formed
Long non-coding RNA (lncRNA)Non-coding RNA with a length greater than 200 nucleotides
Messenger RNA (mRNA)A protein-coding RNA molecule
MicroRNA (miRNA)Small RNA molecule (approximately 21–25 nucleotides long) that negatively regulates gene expression post-transcriptionally
miRNA mimicA synthetic RNA molecule designed to resemble an endogenous miRNA, typically used to study its function
miRNA processingThe conversion of an immature miRNA into a mature miRNA by RNA endonucleases
Post-transcriptionalAn event that occurs after the transcription of DNA to RNA
Post-translational modificationA step in protein biosynthesis where polypeptide chains undergo modifications in order to form the mature protein product
Primary miRNARNA molecule that is cleaved in the nucleus to form a shorter double stranded hairpin (pre-miRNA), which, in his turn, is cleaved to generate the mature miRNA
Ribosomal RNAThe predominant part of the ribosome, essential for protein synthesis
RNA endonucleaseEnzyme that is able to cleave a RNA chain
RNA polymeraseEnzyme that catalyses the transcription from DNA to RNA
RNA splicingProcess where introns are removed and exons are joined either shortly after or concurrent with transcription, in order to form a mature RNA
Small interfering (si)RNA knockdownThe use of a short complementary RNA molecule in order to reduce the expression of a specific gene
TranscriptionThe process where a particular DNA segment is transcribed into RNA by the enzyme RNA polymerase
Transcription factorProtein that can activate or repress the transcription of a gene, by binding to a regulatory DNA sequence (eg, in the gene promoter)
TranslationThe process in which mRNA is converted to proteins