Epigenetics?!? Did anyone see NovaScienceNow last night?

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I think we have at least one biologist here, so can anyone give us a little info on epigenetics?

What I got from the show was that certain chemicals control expression of genes. They can repress genes and activate genes. In fact, they described it as another level of programming of our dna. They used the analogy of dna=hardware, and epigenetics=software. The difference between skin cells and neurons are not in the dna but in the epigenetics. The most interesting idea was that not only can you change your epigenetics (although they did not directly discuss mechanisms for changing your epigenetics) but that you can pass them on to your decendants also.

My first question would be what exactly are some mechanisms for changing your epigenetic programming (either good or bad)? Also, when you pass on your epigenetic programming to your decendants, does it pass down your current programming or do sperm and egg cells have their own programming?

Also, as an aside, it looks like Lamarck wasn't completely wrong after all. Good for him.

Are you asking about what the biochemistry is, or what you can do to reprogram your genome? Not that I can answer, but if you are more specific, someone with more knowledge can give you a better answer.



Both. For the general programming of sperm and eggs, search for sex-regulated or sex-dependent gene regulation or parental imprinting, and perhaps for methylation. One common principle in mammals is that sperm tries to program the fetus to grab as many resources as possible from the mother. For the father, getting better offspring at the expense of the mothers future reproduction is adaptive, if he can get more offspring with another female. It is normally in the female's interest to spread her metabolic resources over several pregnancies, so she programs her eggs to limit how much the fetus grabs, countering the epigenetic program of the copies of the relevant genes which come from the father.

Evidence that epigenetic programming can happen even after fertilization is fairly recent:
http://www.newscientist.com/article/dn4 ... study.html
And the follow up:
http://www.newscientist.com/channel/hea ... r-ate.html

Another article gives a partial answer to your first question. Smoking and bad diet is not a good thing for the epigenetic programming you will give to your kids:
http://www.newscientist.com/channel/hea ... vices.html

Gromit

pm me for more later.... im busy trying to finish my thesis atm ect...

but epigenetics deals with genetics that dont directly effect the dna sequence. (no mutations ).. so yes; gene expression control... dna methylation for example... or x inactivation

there's a whole lot lot of mechanisms for this kind of stuff... it's definitely a new field i like it cause i think it demonstrates nicely how we can be so genetically identical to other organisms and yet be so phenotypically different.

i will also add that.... the results of a person's epigentic program is not in itself heritable to offspring... but the mechanisms through which it occurs are conserved... this is one thing that gives rise to variation in offspring ect

gotta run

I was just reading a book that touched on this. It is so amazing how simple and complex such a thing as our genes and DNA are. I don't know what got me started on learning about this kind of stuff just recently, but it fascinates me now.

yeah, did you know your genes gave you gills at one point during your development? and that other genes later turned on to reabsorb them as you develope?