Long interspersed nuclear element
noun, plural: long interspersed nuclear elements
A form of interspersed repeat specialized for uncoupling interchromosomal gnene conversion
The repeated sequences occur as multiple copies of nucleic acids in the genome. These repeats may involve the DNA or the RNA. There are three major types of repeated sequences: (1) terminal repeats, (2) tandem repeats, and (3) interspersed repeats. Interspersed repeats are repeated sequences where the copies are nonadjacent and dispersed throughout the genome. Examples of interspersed repeats are Alu elements and long interspersed nuclear elements (or LINEs).
LINEs are interspersed repeats that are specialized for uncoupling interchromosomal gene conversion, as opposed to Alu elements that are specialized for uncoupling intrachromosomal gene. Both of them though are essential in allowing genes to evolve by uncoupling the gene conversion network thereby promoting evolution and the development of new species. In humans, LINEs make up about 21.1% of the human genome.
LINEs are also a type of retrotransposons. A LINE could carry about 7000 base pairs. As a retrotransposon, a LINE is amplified by first undergoing reverse transcription. The DNA copy is then integrated back to the genome but at a different position.
- Long interspersed nucleotide element
- Long interspersed element