Scientists from the University of Edinburgh have conducted research that indicates not all traits are directly the result of DNA. That is, the findings indicate that protein spools called histones, around which the DNA is wound in the chromosomes, can determine whether genes are turned on or off. By determining what genes are turned on or off the histones affect the traits of the carrier of the genes. Moreover, naturally occurring changes in histones that affect gene expression can be passed on from parent to child. Per the article:
Scientists studied proteins found in cells, known as histones, which are not part of the genetic code, but act as spools around which DNA is wound. Histones are known to control whether or not genes are switched on. Researchers found that naturally occurring changes to these proteins, which affect how they control genes, can be sustained from one generation to the next and so influence which traits are passed on....The study, published in Science, was supported by the Wellcome Trust and the EC EpiGeneSys Network.
Aren't the histones inherited?
They are inherited but that doesn't make them DNA. DNA consists only of genes and histones are not genes. They affect genes, in terms of which genes are turned on, without being genes themselves. In this they affect what traits a person gets. Maybe some day in the future we will develop substances that can safely simulate histones to turn off disease causing genes or genes that produce undesirable traits such as baldness or acne.
Then they should call it the "DNA Package". Does that mean we all have the same double helix, but it depends on what gene is activated by each histone as to what makes us different?
Except it isn't really part of the DNA. It isn't part of the double-helix structure. It's just stuff that affects the protein-coding function of that particular segment of the DNA itself. Essentially, it's scaffolding which keeps the long helix structures of DNA from breaking apart under the various pressures to which they're subjected. That scaffolding can have some effect on macro (organism level) expressions of the genes is what this article is saying.
It's a difference between what DNA is and what that DNA does, if you want to look at it that way, if that clears it up any. We have a huge percentage of our genes that would do something if they were able to, but these histone protein-scaffolds prevent certain genes from manufacturing proteins and being expressed in the organism.
The point of the article is that the given set of on-off switching of these histones can be passed on to our descendants, just as the genes themselves are.
We absolutely do not all have the same genes Don. Except for identical twins we all have different genes that do not depend on histones to make them different. That is, suppose two people have identical histones. They may still have different traits because they have different genes independently from their histones. The other side of the coin is that two identical twins (who have the same genes) might not have exactly the same traits because the histones of one might have changed naturally and, in so doing, turned off a gene in him or her that is on in the other one.
Thanks guys, I think I got it .