Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

A definition of dominant mutation

  1. Mar 25, 2009 #1
    This is a question of semantics(?). Biologists are not known to be gods of well-definedness, but if there actually exists an argument over the following question (even a possibility), then I might get some credit back on some classwork.

    What is the definition of a dominant mutation (of a nucleotide of an allele at some locus)?

    1. That the mutation yields a new allele which is necessarily dominant w.r.t. to the un-mutated (old) allele.

    2. That the mutation yields a new allele which is necessarily dominant to "other" alleles (or perhaps co-dominant with the unmutated version).

    Co-dominance of two alleles at a locus implies that they are both equally dominant over other alleles.
  2. jcsd
  3. Mar 25, 2009 #2

    Andy Resnick

    User Avatar
    Science Advisor
    Education Advisor

    My understanding of "autosomal dominant" is that the phenotype is displayed under heterogeneous expression. In addition, "dominant negative" mutations mean that the mutated gene product affects the function of the normal gene product (a 'gain of function' mutation).

    Does that help?
  4. Mar 25, 2009 #3
    Not good enough.

    Is "dominance" ordered for a set of alleles? Are there different levels of dominance? The term dominance itself is too vague.

    (sure gain of function mutations are "usually" dominant; however, silent mutations of dominant alleles also retain dominance... in fact co-dominance with the non-mutated versions... over time - generations - they may come into equal allele frequencies... whatever the actual values.)
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Similar Discussions: A definition of dominant mutation
  1. Mutations in humans (Replies: 6)

  2. Mismatches & mutations (Replies: 2)

  3. P53 mutation (Replies: 1)

  4. Mutation balance (Replies: 2)

  5. Evolution and mutation (Replies: 21)