Transposition of IS elements
http://shomusbiology.weebly.com/
Download the study materials here-
http://shomusbiology.weebly.com/bio-m...
A transposable element (TE) is a DNA sequence that can change its position within the genome, sometimes creating mutations and altering the cell's genome size. Transposition often results in duplication of the TE. Barbara McClintock'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.
An insertion sequence (also known as an IS, an insertion sequence element, or an IS element) is a short DNA sequence that acts as a simple transposable element. Insertion sequences have two major characteristics: they are small relative to other transposable elements (generally around 700 to 2500 bp in length) and only code for proteins implicated in the transposition activity (they are thus different from other transposons, which also carry accessory genes such as antibiotic resistance genes). These proteins are usually the transposase which catalyses the enzymatic reaction allowing the IS to move, and also one regulatory protein which either stimulates or inhibits the transposition activity. The coding region in an insertion sequence is usually flanked by inverted repeats. For example, the well-known IS911 (1250 bp) is flanked by two 36bp inverted repeat extremities and the coding region has two genes partially overlapping orfA and orfAB, coding the transposase (OrfAB) and a regulatory protein (OrfA). [1] A particular insertion sequence may be named according to the form ISn, where n is a number (e.g. IS1, IS2, IS3, IS10, IS50, IS911, IS26 etc.); this is not the only naming scheme used, however. Although insertion sequences are usually discussed in the context of prokaryotic genomes, certain eukaryotic DNA sequences belonging to the family of Tc1/mariner transposable elements may be considered to be, insertion sequences. [2] Source of the article published in description is Wikipedia. I am sharing their material. © by original content developers of Wikipedia.
Link- http://en.wikipedia.org/wiki/Main_Page
Transposition of IS elements biology major rutgers | |
| 95 Likes | 95 Dislikes |
| 20,625 views views | 750K followers |
| Education | Upload TimePublished on 2 Feb 2013 |
Không có nhận xét nào:
Đăng nhận xét