Insertion (genetics)

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In genetics, insertion means the incorporation of additional nucleotides or DNA sequences into a DNA sequence in the case of a gene mutation .

properties

An insertion leads to a frame shift ( frame shift ), unless integer multiples of three nucleotides in the sense of triplet codons are incorporated. An insertion can have the consequence, especially in the case of a reading frame shift, that the gene product which is encoded on the gene can no longer be produced correctly.

The deletion of sequences, which is referred to as deletion , has effects similar to the insertion of nucleotide sequences . Indel is an umbrella term for insertions and deletions. Since the unambiguous assignment after several different insertions and deletions is problematic, these ambiguous cases are combined into one category without more precise classification as indel .

In the case of a chromosome mutation , a chromosome has an additional piece internally after an insertion.

Inverted repeats a facilitated insertion of DNA used in the genome of the host . These are used by some integrating viruses (e.g. adeno-associated viruses , HIV ) or mobile genetic elements (such as retroelements , transposons, or integrating bacterial plasmids ).

In biochemistry and molecular biology, targeted insertions are occasionally used in a cloning , a protein design , a vector design or also randomly in a mutagenesis .

example

The reading frame shift can be explained using an example. The sentence

I ONLY LIKE AN ICE CREAM

makes sense. Each word consists of three letters, as an analogy to the triplet codon in DNA. Similarly, the information is also available on a gene , here the three nucleotides are always combined into a triplet codon. During translation , three nucleotides each code for one amino acid .

When inserting a letter, the meaning is changed while maintaining the three-letter grid:

I XMA GNU REI NEI S

literature

  • Jeremy M. Berg, John L. Tymoczko, Lubert Stryer : Biochemistry. 6 edition, Spektrum Akademischer Verlag, Heidelberg 2007. ISBN 978-3-8274-1800-5 .
  • Donald Voet, Judith G. Voet: Biochemistry. 3rd edition, John Wiley & Sons, New York 2004. ISBN 0-471-19350-X .
  • Bruce Alberts , Alexander Johnson, Peter Walter, Julian Lewis, Martin Raff, Keith Roberts: Molecular Biology of the Cell , 5th Edition, Taylor & Francis 2007, ISBN 978-0815341062 .

Individual evidence

  1. ↑ M. Garcia-Diaz, TA Kunkel: Mechanism of a genetic glissando: structural biology of indel mutations. In: Trends Biochemical Sciences (2006), Volume 31, Issue 4, pp. 206-214. PMID 16545956 .
  2. ^ TA Kunkel: Evolving views of DNA replication (in) fidelity. In: Cold Spring Harbor Symposium Quantitative Biology (2009), Volume 74, pp. 91-101. doi : 10.1101 / sqb.2009.74.027 . PMID 19903750 ; PMC 3628614 (free full text).