Why are Some Mutant Phenotypes Dominant? Research Paper by fbgenius

Why are Some Mutant Phenotypes Dominant?
A research paper on why some mutant phenotypes are dominant.
# 153736 | 2,710 words | 15 sources | APA | 2007 | GB
Published on Nov 26, 2013 in Biology (Molecular and Cell) , Biology (Genetics)

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This paper describes, with appropriate examples, the various ways in which mutations result in dominant phenotypes. The paper addresses mutations that result in a loss of the function of the product of a gene, mutations that result in a gain of function, and mutations that are dominant negative mutations. The paper also explores some of the ways in which diseases are caused by only one mutated allele. The paper concludes that it appears that dominant mutations arise due to the state of the mutated product, and that the presence of the normal product is not enough to prevent the disease. The paper includes diagrams and photographs.

Loss of Function Mutations
Dominant Negative Mutations
Gain of Function Mutations

From the Paper:

"The vast majority of mutant phenotypes in diploid organisms are inherited in a recessive manner; that is, a mutation in one allele of a pair of homologous genes has no phenotypic effect, and mutational studies have put the figure of these mutations at over 90% (1). This is an advantage that diploid organisms have over haploids: one normal gene product is almost always sufficient for a normal phenotype. However, a large number of diseases are shown, usually by simple pedigree analysis, to be dominant. In these diseases, the normal allele is not sufficient for a normal, or 'fitter', phenotype.
"There is not just one simple mechanism for this phenomenon, but it is almost always due to an altered or de novo function. For example, a gene may be mutated in a way that produces a protein that adversely affects the product of the corresponding normal allele, which would result in an effective loss of the protein. This is a negative effect, where the protein acts as a sort of toxin. In this essay, I will describe, with appropriate examples, the various ways in which mutations result in dominant phenotypes.
"As is expected, the dominant nature of mutations complex. Rarely do we find cases of complete recessivity or dominance, and various degrees of dominance can be seen, as well as variable penetrance (phenotype sometimes not present) and expressivity (varying mutated phenotypes)."

Sample of Sources Used:

  • Wilkie, A.O., 1994. The molecular basis of genetic dominance. Journal of Medical Genetics, 31: 89-98
  • Strachan, T., Read, A.P., 2004. Human Molecular Genetics, 3rd ed. Garland Science.
  • Seidman, J.G., Seidman C., 2002. Transcription factor haploinsufficiency: when half a loaf is not enough. www.jci.org/articles/view/15043
  • Li, D.Y., Faury, G., Taylor, D.G., et al. 1998. Novel arterial pathology in mice and humans hemizygous for elastin. J. Clin. Invest., 102: 1783-1787
  • Falls, J.G., Pulford, D.J., Wylie, A.A., Jirtle, R.L. 1991. Genomic Imprinting: Implications for Human Disease. American Journal of Pathology 154: 635-647

Cite this Research Paper:

APA Format

Why are Some Mutant Phenotypes Dominant? (2013, November 26) Retrieved January 28, 2022, from https://www.academon.com/research-paper/why-are-some-mutant-phenotypes-dominant-153736/

MLA Format

"Why are Some Mutant Phenotypes Dominant?" 26 November 2013. Web. 28 January. 2022. <https://www.academon.com/research-paper/why-are-some-mutant-phenotypes-dominant-153736/>