JUMPING GENES AND RNA BRIDGES – SCIENCE
News: Scientists at the Carnegie Institution found
that some genes were able to move around within the genome. These genes were
called Jumping genes or transposons.
What’s in
the News?
·
Transposons influence the effects of genes
and are called the tools of evolution, for their ability to
rearrange the genome and introduce changes.
·
More than 45% of the human genome
consists of transposable elements.
o
They create mutations in genes and lead to
diseases.
·
However, most of the transposons have
themselves inherited mutations and have become inactive, and thus can’t move
around within the gnome.
Jumping genes (Transposons)
·
The name
of the jumping gene is IS110, which stands for Insertion
Sequence, and such sequences are found in an array of life-forms,
including bacteriophages, bacteria, plants, worms, fruit flies, mosquitos,
mice, and humans.
They roam around the
body, cutting and pasting themselves, repairing DNA and modifying it
daily.
Bridge
RNA
·
Bridge RNA refers to a type of RNA (Ribonucleic Acid) molecule
that plays a crucial role in the process of DNA rearrangement in
certain organisms.
·
Bridge RNAs act as molecular bridges
between different DNA segments during this intricate process of DNA
rearrangement.
Significance
of Jumping genes:
·
The IS110 bridge recombination system expands
the diversity of nucleic-acid-guided systems beyond CRISPR and
RNA interference.
·
It offers a unified mechanism for the three
fundamental DNA rearrangements — insertion, excision and inversion — that are
required for genome design.
o
DNA insertion is a genetic process in which a segment of DNA is added
to a different DNA segment,
o
Excision is a mechanism in which a damaged DNA segment is
removed, and
o
Inversion is a method in which a piece of DNA in a chromosome
gets reversed.
·
With bridge RNA, researchers
can program both the target and the donor sequence of DNA so they can mix
and match any two that they want, whereas the guide RNA in CRISPR-Cas9
systems can specify only the target DNA sequence to be cut, not the one to be
added in.