Epigenetics is a term that is increasingly being heard of outside of molecular biology or genetics.
One of my interests is how gene regulation works, how the molecules that control genes do their thing. You can think of epigenetics as gene regulation through controlling the availability of genes to be used or not.
While it’s fairly easy to offer some examples of epigenetics, it’s harder to present it a balanced way, in part because understanding it needs a little context, a little explanation of how it fits into the rest of the what‘s going on in the nucleus—the place the DNA is stored in our cells—while our bodies develop and grow.
This TED lecture by Dr. Courtney Griffin from the Cardiovascular Biology Research Program at the Oklahoma Medical Research Foundation gives some of the background.
It’s a little drier than many TED lectures*—but a lot lighter than formal lectures on the topic!—and worth viewing if you’d like to know more about epigenetics.
A lighter presentation is this from NOVA ScienceNow by Neil Tyson. Lest you think he’s not a star, Neil Tyson has over a million twitter followers.** (And counting.)
A quibble I have with this presentation is that by focusing on just one gene, some readers might come away with the idea that most of our genes will have similar trans-generational effects. In practice, there are only a few examples (from different species) known.***
As I was saying my own interests are with how the molecules that control genes do their thing. The video below has animations of molecules carrying out some of the things that take place in epigenetic regulation of genes. If you’re not familiar with molecular biology, don’t worry too much about precisely what is doing what, just the gene nature of the thing that the animation shows. It’s quite a jump from what Tyson presents to this, but this is where all the action happens.
One quibble—yes, another quibble!—about that video is that in reality the interior of cells is crowded. There‘s a wonderful illustration of how crowded the interior of cells are in a model of the cytoplasm I’ve shown readers before. If you haven’t seen it before, check it out. (Think about how things get to interact with one-another given the sheer density of stuff in a cell.) The video above has all the ‘other’ molecules stripped away. It’s understandable, it’d be impossible to see anything in the animation otherwise, but readers not knowing better might think everything takes place in empty expanses of water!
A video from an earlier post, Animating our DNA, shows an animation of chromatin and chromosomes (from about 4:45 through to about 5:30 in the video, but watch it from the start).
All these give some glimpses of what epigenetics involves, but I’m not convinced they convey the full picture well because a wider explanation of the context epigenetics works within is needed to give it perspective.**** Goodness knows if I’d find time, but it’d be good to present some sort of introduction to epigenetics that I think is more satisfying – at least more satisfying to me!
Another quibble over the third (last) video is the representation of the condensed chromatin. As you can see I could do this all night…!
* Partly because the slides are closer to student lecture material than what you’d see in, say, a popular science TV program.
** Hat tip to David Kroll (@davidkroll) for that tidbit. Via twitter, of course.
*** Thus far, anyway. I can’t help wonder if this extrapolation from a few examples partly explains many of the over-stated claimed about epigenetics in the mainstream media, or the martketing for ‘remedies’ that use the term epigenetics to create an impression of being based in science. (There are some medicines being developed that are using epigenetics for their effect – for example a number of anti-cancer treatments. More about that in a later post, perhaps.)
More articles (with epigenetic themes) on Code for life: