Transposable element

Mobile genetic elements that can change their position within a genome

Transposable elements (TEs), also known as jumping genes, are sequences of DNA that can move or transpose themselves to new positions within the genome of a single cell. They are found in almost all organisms and can be classified into two main types: DNA transposons and retrotransposons.

History

The concept of transposable elements was first discovered by Barbara McClintock in the 1940s through her work on maize (corn). Her pioneering research earned her the Nobel Prize in Physiology or Medicine in 1983.

Types

DNA Transposons

Diagram of a DNA transposon.

DNA transposons move by a "cut and paste" mechanism, where the transposon is excised from one location and inserted into another. This process is facilitated by the enzyme transposase, which is encoded by the transposon itself.

Retrotransposons

Retrotransposons move by a "copy and paste" mechanism. They are first transcribed into RNA, which is then reverse-transcribed into DNA by the enzyme reverse transcriptase. This new DNA copy is then inserted into a new location in the genome.

Function and Impact

Transposable elements can have significant effects on the genome. They can cause mutations, alter the genetic code, and contribute to genetic diversity. In some cases, they can disrupt gene function or regulatory regions, leading to disease. However, they can also play a role in evolution by creating new genes or regulatory elements.

Applications

Transposable elements have been harnessed in genetic engineering and biotechnology. They are used as tools for gene delivery and mutagenesis in various organisms.

Related pages

• Gene
• Genome
• Mutation
• Genetic engineering

References

• McClintock, B. (1950). "The origin and behavior of mutable loci in maize." Proceedings of the National Academy of Sciences, 36(6), 344-355.
• Feschotte, C., & Pritham, E. J. (2007). "DNA transposons and the evolution of eukaryotic genomes." Annual Review of Genetics, 41, 331-368.

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  Composite transposon

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  DNA transposon