A new study analyzes the evolution of epigenetic mechanisms of bacteria to human -
After the emergence of single-celled organisms, there are a few billion years, nature began experimenting with how to diversify the function of genes without changing the DNA sequence, so that the blue print is retained, but allows gene products have different functions. As multicellular organisms evolved, the maintenance process and function were provided by mechanisms that are called "epigenetic". Epigenetics allow genes function differently by adding chemical "tags" of DNA or proteins that surround DNA. Recent studies suggest that in more developed eukaryotes, changes in the protein that helps regulate the DNA again how "tag" chemical will be attached to DNA and vice versa.
A new study published by the School of Medicine researchers at Boston University in the Journal of Genetics and epigenetics , provides a comparative analysis of the evolution of epigenetic mechanisms prokaryotes (bacteria) to simple eukaryotes (multi-cellular) to more complex eukaryotic (human). Bacteria have evolved for billions of years, and even at this early stage, nature has begun the process to enable the bacterial DNA to perform various functions without changing the order by which DNA is organized. This was achieved by adding a "tag" to a chemical sub-units of DNA. The group of atoms which joins may vary depending on the organism. This simple change is important for the survival of bacteria and allows bacteria to fight against infections. It is striking that although the "tag" binding site moved to a different subunit of DNA as developed eukaryotes. Viruses have also learned to use this process "marking" to their advantage. HIV virus which causes AIDS, Cache immune system of the individual by removing a "tag" particularly proteins that fold DNA.
According to corresponding author Sibaji Sarkar, PhD, professor of medicine at BUSM, it is interesting to see how nature has moved the site of 'tag' addition of bacteria to mammals. "The addition of 'marking' proteins that are involved in DNA folding in eukaryotic provided another dimension," says.
He added, "If we observe closely the process of regeneration in some eukaryotes, including zebrafish, when a part is cut, it is clear that the pool of genes present in the DNA provides the healing process necessary to regenerate the body section. We can save a lot of knowledge to understand how stem cells can become many types of organs by studying this process. "It seems that epigenetic mechanisms regulate this process. The most striking event that describes this type of multiple training facets of organs and tissues of a cell (fertilized egg) is embryogenesis.
When mammals reproduce, the DNA sequences that are inherited can not be changed, but from the moment the sperm fertilizes the egg, each step takes place according to a set of rules until the tissues and organs are differentiated. Different sets of genes are used for each stage of development. for example, "tags" in egg after fertilization are erased, then rewritten. proteins that rewrite this process are governed by the same proteins that fold DNA into the egg of the mother. It is therefore reasonable to believe that the characteristics of proteins mom folding may dictate what type of "tag" will take place in its DNA offspring. It is known that epigenetic alterations of "marking" are governed by the environmental effects. The authors suggest that environmental factors and lifestyle of the mother will therefore affect the "marking" of the offspring of the DNA, which will dictate how genes descendants will be used. Interestingly, epigenetic changes are also held throughout life depending on the lifestyle of the person.
This article includes a description of the changed epigenetic changes that can lead to many types of diseases, including metabolic syndrome, cardiovascular disease, autoimmune diseases, neurological disorders, aging and cancer .
The authors proposed another hypothesis that could explain how cancer cells increase the number of copies of genes for tumor and reduce or eliminate tumor gene inhibitor. Sarkar added: "Cancer cells may hijack a mechanism device in normal cells that provides the way how the methyl labeled DNA will be untagged by cutting the DNA at the label site and repair. It's an interesting idea to be tested. "
The epigenetic process of" marking "used by bacteria living in human bodies is a gold mine for understanding the normal functions of cells and determine where, when, and how those steps deviate from normal behavior to cause disease conditions, a process that is still not well understood.
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