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DNA mutation

There are five stages of DNA mutation that consists of Normal, Nonsense mutation, Missense mutation, Frame Shift, and Frame Shift. Normal - The information DNA 3 bases (codons) is translated into 1 amino acid each to synthesize the protein. Nonsense mutation – DNA 1 molecule is mutated to another DNA. In this case, if the mutated codon is changed to an instruction to terminate the synthesis of the protein, normal protein (eg, GAA → TAA) is not synthesized. Missense mutation - 1 DNA molecule is mutated to another DNA. In this case, if the mutated codon is changed to what means another amino acid, the desired protein (eg, GAA → CAA) is not synthesized. Frame Shift (1 base deletion) - DNA 1 to 2 bases in the middle of sequence Deletion of DNA mutation. There is one sequence below that base, the arrangement of codons changes greatly. Protein of interest is not synthesized. Also, in this case, if the middle codon is often turns into an instruction to terminate the synthesis of the protein.

Frame Shift (Addition of 1 base) - A rare mutation in which DNA 1 to 2 bases are added in the middle of a DNA sequence. There is one sequence below that base, the arrangement of codons changes greatly. Protein of interest is not synthesized. Also, in this case, the middle codon often changes in order to terminate the synthesis of the protein.

How DNA Mutation Is Caused

Mutation of DNA can be the source of cancer. On the other hand, DNA mutation also results in a diversification of antibodies that can act as immunity in the body.

All organisms store and inherit genomic information using chemical substances called DNA as the storage medium.

Replication polymerase δ can copy DNA correctly and can find out the error by themselves.

About 100,000 scratches occur on each cell per day due to metabolic reactions such as respiration, as well as radiation and ultraviolet rays, but these scars cannot continue copying, using DNA replication polymerase. It is believed to have stopped functioning. When copying stops due to DNA scratches that occur frequently, the replication polymerase switches to a special polymerase group called TLS polymerase, so that copies are taken over and not stopped. It is considered that an error occurs in copying by TLS polymerase, and it becomes a major cause of mutation.

Work Cited

・Hironao NUMABE, M.D. 'Tokyo Medical University Department of Pediatrics Genetics Study Group''. '''

https://www.tokyo-med.ac.jp/genet/dmu-j.htm.

・Toshiichi Takeda, Kouji Hirota. Kyoto University. Research Results. Established 03, Dec. 2015.

http://www.kyoto-u.ac.jp/ja/research/research_results/2014/150202_2.html.

http://dx.doi.org/10.1093/nar/gkv023.