Ickekodande

Ickekodande is a term used in Swedish-language genetics and molecular biology to denote non-coding DNA — regions of the genome that do not encode protein sequences. The word combines 'icke' (not) with 'kodande' (coding).

Definition and scope: Non-coding DNA encompasses introns, untranslated regions of transcripts (UTRs), promoters, enhancers, insulators, repetitive elements, and various classes of non-coding RNA genes such as tRNA, rRNA, microRNA and long non-coding RNA. In many organisms these regions are interspersed with protein-coding genes and can regulate when, where, and how genes are expressed.

Functions and significance: Although they do not produce proteins themselves, non-coding regions influence transcription, RNA processing, chromatin structure, and genome stability. Regulatory elements control transcription factor access and gene networks; non-coding RNAs can modulate gene expression post-transcriptionally or alter chromatin states. The amount and composition of non-coding DNA vary between species and contribute to differences in genome architecture and regulation.

Historical perspective: The idea that non-coding DNA is largely without function persisted for many years (the notion of "junk DNA"), but modern genomics has identified numerous functional elements and transcripts within these regions. Ongoing research aims to map regulatory landscapes and understand how non-coding variation contributes to development, evolution, and disease.

See also: non-coding DNA, regulatory elements, introns, untranslated regions, non-coding RNAs.