Transposable elements (q.v.) that mobilize via an RNA intermediate. Each DNA segment in the host chromosome is transcribed into RNA and then reverse-transcribed via a reverse transcriptase (q.v.) into a DNA segment. This is reinserted into the host genome, usually at a new site. Retroposons are the most abundant transposons in plants. These elements account for 70% of the nuclear DNA in maize. The best-understood retroposons are retroviruses (q.v.) such as HIV (q.v.). Retroposon is a shortened form of retrotransposon, which also appears in the literature. See Chronology, 1985, Boeke et al.; 1990, Biessmann et al.; centromere, copia elements, repetitious DNA, telomere, Ty elements.
Subjects: Genetics and Genomics — Chemistry.