Epigenetic trait

Thymine can also be described as 5-methyluracil. Other methylated pyrimidines exist in some nucleic acids e.g., methylation of cytosine (Fig. 3-30) in both DNA and RNA has important biological effects with respect to protection of the genetic material and its expression. Methylation is considered to be of central importance in controlling phenotypical traits whose inheritance appears to violate the usual rules of Mendelian genetics, and hence are termed epigenetic traits. 

Epigenetics An epigenetic trait is a stably inherited phenotype resulting from changes in a chromosome without alterations in the DNA sequence. Epigenetic marks include cytosine (hydroxy)methylation and various histone modifications. 

An important aspect of the histone code theory is that some modifications can be passed on during cell division. As a result histone modification patterns including histone acetylation serve as a means to store inheritable traits of an organism which are not DNA encoded. This kind of information is generally termed epigenetic information. 

Kaminsky, Z., Petronis, A., Wang, S.C., Levine, B., Ghaffar, O., Eloden, D. and Eeinstein, A. (2008) Epigenetics of personality traits An illustrative study of identical twins discordant for risk-taking behavior. Twin Research and Human-Genetics, 11, 1-11. 

True HE, Berlin 1, Lindquist SL (2004) Epigenetic regulation of translation reveals hidden genetic variation to produce complex traits. Nature 431 184—187 Tuite ME (2000) Yeast prions and their prion-forming domain. Cell 100 289—292... 

Because certain disease states can be linked to epigenetic states, it is possible for one individual to develop a disease while his or her identical twin does not. Susceptibility to diseases is often a family trait, but the actual mechanism of getting the disease may require epigenetic changes in the DNA of a ceU. Epigenetic changes are known to be important, CH3 the field of cancer research, but... 

Halfinann, R., Lindquist, S. (2010). Epigenetics in the extreme prions and the inheritance of environmentally acquired traits. Science, 330, 629-632. 

Inheritance of phenotypes, like disease susceptibility, has traditionally been associated with genetic information stored in DNA s genetic code. During the last decade, however, research has shown that further, non-genetic traits called epigenetic factors, play a role in phenotype inheritance. 

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