Mutagen

You don't need to be Editor-In-Chief to add or edit content to WikiDoc. You can begin to add to or edit text on this WikiDoc page by clicking on the edit button at the top of this page. Next enter or edit the information that you would like to appear here. Once you are done editing, scroll down and click the Save page button at the bottom of the page.

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Phone:617-525-6884

Please Take Over This Page and Apply to be Editor-In-Chief for this topic: There can be one or more than one Editor-In-Chief. You may also apply to be an Associate Editor-In-Chief of one of the subtopics below. Please mail us [2] to indicate your interest in serving either as an Editor-In-Chief of the entire topic or as an Associate Editor-In-Chief for a subtopic. Please be sure to attach your CV and or biographical sketch.

In biology, a mutagen (Latin, literally origin of change) is a physical or chemical agent that changes the genetic information (usually DNA) of an organism and thus increases the frequency of mutations above the natural background level. As many mutations cause cancer, mutagens are typically also carcinogens. Not all mutations are caused by mutagens: So-called "spontaneous mutations" occur due to errors in DNA replication, repair and recombination of DNA sequences.

Effects of mutations

The changes in nucleic acid sequences by mutations include substitution of nucleotide base-pairs and insertions and deletions of one or more nucleotides in DNA sequences. Although many of these mutations are lethal, or cause serious disease, some have minor effects, as the changes they cause in the sequence of encoded proteins are not significant. Many mutations cause no visible effects at all, either because they occur in introns, or because they do not change the amino-acid sequence, due to redundancy of codons.

Genetic drift

The change in a population’s genetic material due to the accumulation of random chance is called drift and serves as a molecular clock. In general, the more nucleotide differences between two organisms, the more time has elapsed since their last common ancestor. Though it is difficult to determine in many organisms, estimates for mutation rates have been made for both E. coli and eukaryotes. It was estimated that in these organisms about one nucleotide in every 10¹⁰ is changed and continues through reproduction to future generations of cells.

Discovery of mutagenesis

In the 1920s, Hermann Muller discovered that x-rays caused mutations in fruit flies. He went on to use x-rays to create Drosophila mutants that he used in his studies of genetics. He also discovered that x-rays did not only mutate genes in fruit flies, but also had effects on the genetic makeup of humans.^[1]

Nature of mutagens

Mutagens are usually chemical compounds or ionizing radiation. Mutagens can be divided into different categories according to their effect on DNA replication:

• Some mutagens act as base analogs and get inserted into the DNA strand during replication in place of the substrates.
• Some react with DNA and cause structural changes that lead to miscopying of the template strand when the DNA is replicated.
• Some work indirectly by causing the cells to synthesize chemicals that have the direct mutagenic effect.

The Ames test is one method to determine how mutagenic an agent is.

Examples

• Nitrous acid, (HNO₂) Deaminating agent
• UV Radiation, thymine dimer formation
• Sodium azide, (NaN₃)
• Gamma and Alpha Radiation, ionising radiations
• Transposons, autonomous DNA fragment relocation/multiplication
• Base analogues, substitutes
• Bromine and some of its compounds,
• Ethidium bromide (EtBr), and other intercalating agents.
• Bromouracil,Alkylating Agent
• Vinca Alkaloids, Natural Plant Alkaloid

Mutagens in fiction

In science fiction, mutagens are often represented as substances that are capable of completely changing the form of the recipient.

• The Inhumans of Marvel Comics utilize a mutagen called the "Terrigen Mist".
• The Teenage Mutant Ninja Turtles were supposedly created by means of mutagens, as well as their master Splinter and (in the 1987 cartoon) their enemies Bebop and Rocksteady.
• In the Street Fighter movie, a bag of mutagens is used by General Bison to transform Carlos Blanka into a monster.
• In Lego's Bionicle franchise, the water surrounding the pit is mutagenic, causing mutation in most of the major characters who enter the water.

References

See also

• Carcinogen
• DNA repair
• Genetics
• Pesticide
• Teratogen

cs:Mutagen da:Mutagen de:Mutagen et:Mutageenfr:Mutagène he:מוטגן lv:Mutagēns lt:Mutagenas nl:Mutageen ja:変異原sr:Мутаген sv:Mutagen uk:Мутаген ur:مُطَفِّر

WikiDoc Help Menu Quick Start.. Get Started Here! How to Login How to Search Pages How to Start a New Page How to Edit a Page Cheat Sheet Editing basics Learning Basic Formatting How to make Links in WikiDoc & to External Sites How to Make Lists How to Ignoring Formatting Adding References or Footnotes to Articles Tracking Changes You Have Made How to Put an Article Into a Category When Multiple Topics Should Go To The Same Page (MI, Acute MI, AMI) Using Redirection Advanced editing How to Make Tables How to Insert Images and Other Media How to Add Video Help:How to Make Columns Web Colors How To Make Templates How to Move Pages Inserting Dynamic Dates and Times Inserting WikiDoc Statistics Editing the Table of Contents Communicating your edits Let others know what you changed: The importance of Edit Summaries Minor Edits Edit Conflicts Help Videos You Can Watch Getting Started Video

Acknowledgement and Attribution Regarding Sources of Content

Some of the initial content on this page may be incorporated in part from copyleft sources in the public domain including wikis such as Wikipedia and AskDrWiki. Drug information for patients came from the The National Library of Medicine. Infectious disease information may have come from the Centers for Disease Control (CDC). Differential Diagnoses are drawn from clinicians as well as an amalgamation of 3 sources: 1.The Disease Database; 2. Kahan, Scott, Smith, Ellen G. In A Page: Signs and Symptoms. Malden, Massachusetts: Blackwell Publishing, 2004:3; 3. Sailer, Christian, Wasner, Susanne. Differential Diagnosis Pocket. Hermosa Beach, CA: Borm Bruckmeir Publishing LLC, 2002:7 .