Posted on 01/22/2006 10:33:19 AM PST by Ma3lst0rm
"The genetic sequence is essentially fixed for life, but we believe epigenetic marks are more subject to change," says Feinberg. "The IHF collaboration will let us really test the stability of epigenetics and the passage of those marks from parents to child, perhaps even over successive generations."
At the heart of the center's work is epigenetics' importance in proper cell function and in development. One example of epigenetics is "imprinted" genes--genes whose activity is determined not by the regular dominant and recessive rules of Mendel's genetics, but solely by which parent provided the gene copy. For example, for some imprinted genes only the copy from the mother is used, while for other imprinted genes, only the copy inherited from the father is turned on. (Our cells contain two copies of every gene, one from the mother and one from the father.)
At some point before, during or after egg meets sperm, epigenetic marks such as those used for imprinting must be reset and re-established, so that a gene passed from father to daughter to son is appropriately marked, for example. Knowing how and when this happens, and whether the process can be controlled, has important implications for understanding human development and the viability of animals and stem cells created through somatic cell nuclear transfer, a process colloquially known as "cloning."
(Excerpt) Read more at hopkinsnet.jhu.edu ...
May have being the operative words here.
DNA research has discovered a great deal over the past several decades. The Human Genome Project has mapped our entire genetic code, which consists of a sequence of over 3 billion chemical nucleotide bases. Through a better understanding of our genes, scientists have been able to diagnose the causes of many illnesses faster and more accurately and have found genetic cures for diseases. Doctors can now develop customized treatment plans for patients based on their specific genetic code. The field of genetics has also caused a great deal of controversy as it's jumped into research on cloning, genetically modifying plants and animals, and the possibility of inadvertently creating new and stronger viruses. Although scientists have learned a great deal about the human genome, the majority our DNA remains a complete mystery. Most scientists believe that genes are the crucial part of DNA because they code for proteins. Some non-coding DNA is also known to be important because it provides the timing commands for the coding DNA, telling it when to start and stop replicating. Most people don't realize, however, that less than 2% of the genome codes for the production of proteins. The vast majority of DNA is considered simply "excess baggage." In fact, when the Human Genome Project began, some scientists only wanted to map the sections of genome that coded for protein. Mapping all of the non-coding DNA - referred to as "junk" DNA - was considered a waste of time because it served "no known biological role." Still, the entire genome was mapped, leading to some interesting discoveries.
The "excess baggage" is being found to be very important.
UCSD study shows 'junk' DNA has evolutionary importance
http://www.eurekalert.org/pub_releases/2005-10/uoc--uss101705.php
Non-coding RNAs and Gene Regulation
http://www.thetech.org/genetics/news.php?id=14
Personality Encoded In Junk DNA
http://www.scienceagogo.com/news/20050510012606data_trunc_sys.shtml
That's the problem with so many in the sciences. If they don't know what it does or why it's there, it's either thrown out or is lumped in with something else.
Didn't they do the same with the human brain, claiming we only use a small portion of it, then having to backtrack later?
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