Question

What is transposition and what are the differences between replicative and non replicative transposition?

Answer 1

TRANSPOSITION:- It involves the translocation of small DNA segments from one site called(Donor site ) to another site called (Target site) with the genome. These segments are called transposons. It is a type of DNA recombination and may involve many other DNA rearrangements such as deletion, inversion, etc. The transposons are found in various cells and are called jumping genes. Retrotransposons and DNA transposons are two classes of transposable element

Transposition is of 2 types.

1. Non-replicative transposition:-

This is also called as cut and past translocation and conservative transposition. In this process, the transposon element is cleaved from the donor DNA segment and inserted into the target DNA segment. The transposons as scissors and involves the simple cutting and insertion of the DNA segment from genomes. This reaction is catalyzed by the transposase enzyme.

Application:- transgenesis and mutagenesis induced by insertion

• Replicative transposition;-

In replicative transposition, the transposon element is replicated during translocation. This leads to the formation of an intermediate having a theta configuration. The replicative transposition is a characteristic feature of retrotransposons.

although replicative and non-replicative transposition seems to be different still they are common at the various level as at certain condition non-replicative transposition can be biologically replicative.