Skip to comments.Epigenetics reveals unexpected, and some identical, results
Posted on 01/25/2009 11:03:50 PM PST by neverdem
One study finds tissue-specific methylation signatures in the genome; another a similarity between identical twins in DNAs chemical tagging
Tattoos on the skin can say a lot about person. On a deeper level, chemical tattoos on a persons DNA are just as distinctive and individual and say far more about a persons life history.
A pair of reports published online January 18 in Nature Genetics show just how important one type of DNA tattoo, called methylation, can be. Researchers at Johns Hopkins University report the unexpected finding that most DNA methylation a chemical alteration that turns off genes occurs most often near, but not precisely within, the DNA regions on which scientists have typically focused their studies. The other report, from researchers at the University of Toronto and collaborators, suggests that identical twins owe their similarity not only to having the same genetic make-up, but also to certain methylation patterns established in the fertilized egg.
Methylation is just one of many epigenetic signals chemical changes to DNA and its associated proteins that modify gene activity without altering the genetic information in the genes. Methylation and other epigenetic signals help guide stem cells as they develop into other type of cells. Scientists have long suspected that mishandling methylation and other epigenetic flags could lead to cancer.
The Johns Hopkins group has now shown that DNA methylation is more common at what they call CpG island shores instead of at the CpG islands that most researchers have been studying. CpG islands are short stretches of DNA rich in the bases cytosine and guanine, also known as C and G in the genetic alphabet. (Adenine (A) and thymine (T) are the other DNA bases.) CpG islands are located near the start site of genes and...
(Excerpt) Read more at sciencenews.org ...
Understanding epigenetics will be necessary for regenerative medicine.
Thanks for the epigenetics ping!
Rethinking The Genetic Theory Of Inheritance: Heritability May Not Be Limited To DNA
Science Daily | Jan. 20, 2008 | Unknown
Posted on 01/21/2009 4:17:24 AM PST by decimon
Thanks ApplegateRanch (and neverdem for the topic).
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This would probably explain why food deprivation and other environmental factors can affect children and grandchildren. If I remember correctly, some such affects seem to be stronger in the male line.
I remember reading an article about the study of children born in Holland during the Nazi occupation. There was a deliberate famine inflicted on the population, and infants who were affected during gestation were studied later to assess the impacts.
There were identifiable effects, depending on the time of conception vis a vis the food deprivation of the mother, that carried on to the progeny of those children gestated during the famine.
So the grandchildren of starving mothers were affected, as you have stated.
I read this in Discovery magazine years ago.