An Introduction to Transposons

The human genome project revealed that less than 5% of the human genome is likely to consist of functioning genes. Of the remaining 95% of non-functioning genes, nearly 50% is thought to consist of transposable elements or transposons.

Transposons are often referred to as “jumping genes” as they are segments of DNA which are able to “jump” from location to location within a genome. This "jumping" process is called transposition.

Transposable elements are more abundant in eukaryotic genomes than in prokaryotic genomes. In eukaryotes transposition occurs from one location within a chromosome to another location within the same chromosome, or from one chromosome to a different chromosome. Prokaryotic transposons may transpose amongst chromosomal DNA, between chromosomal DNA and a plasmid, or between two plasmids. There are many different types of transposons which use various methods of transposition.