Transposable elements – Video

Video Link: https://www.youtube.com/watch?v=cwTeIbXHMwU

Transposable elements
For more information, log on to- shomusbiology.weebly.com Download the study materials here- shomusbiology.weebly.com A transposable element (TE) is a DNA sequence that can change its position within the genome, sometimes creating mutations and altering the cell #39;s genome size. Transposition often results in duplication of the TE. Barbara McClintock #39;s discovery of these jumping genes early in her career earned her a Nobel prize in 1983.[1] TEs make up a large fraction of the C-value of eukaryotic cells. They are generally considered "junk DNA". In Oxytricha, which has a unique genetic system, they play a critical role in development.[2] They are also very useful to researchers as a means to alter DNA inside a living organism. Class I (retrotransposons): They copy themselves in two stages, first from DNA to RNA by transcription, then from RNA back to DNA by reverse transcription. The DNA copy is then inserted into the genome in a new position. Reverse transcription is catalyzed by a reverse transcriptase, which is often coded by the TE itself. Retrotransposons behave very similarly to retroviruses, such as HIV. There are three main orders of retrotransposons (other orders are less abundant): Those with long terminal repeats (LTRs): encode reverse transcriptase, similar to retroviruses; LINEs: encode reverse transcriptase, lack LTRs, transcribed by RNA polymerase II; SINEs: do not code for reverse transcriptase, transcribed by RNA polymerase III. Retroviruses can be ...From:Suman BhattacharjeeViews:1 0ratingsTime:09:07More inEducation

More here:
Transposable elements - Video