S3.15 Pimp My Genome: the wonderful world of epigenetics
Kat: Hello, and welcome to Genetics Unzipped - the Genetics Society podcast, with me, Dr Kat Arney. In this episode we take a look at the world of epigenetics - finding out if more than DNA passes on to the next generation, whether Darwin was wrong and Lamarck was right, and how to pimp your genome.
Before we start, another quick plug for my new book, Rebel Cell: Cancer, Evolution and the Science of Life, exploring what we’ve learned so far about where cancer comes from, where it’s going, and how we might finally beat it.
It’s coming out in the UK on the 6th of August and in the US on the 29th September - and is available now to pre-order from rebelcellbook.com - and we’ll have some excerpts coming up in a future episode of the podcast. UK Amazon link (affiliate) https://amzn.to/2BdT5zu
But this time, it’s time to look at a subject I explored in my first book, Herding Hemingway’s Cats: epigenetics. It’s one of the hottest - and most misunderstood - topics in genetics, and one that I have a deep love for, having done my PhD in genomic imprinting - a classic epigenetic phenomenon - a long time before it was cool.
What is epigenetics?
When I give public talks, I can almost guarantee that someone will ask a question along the lines of, “Ah, what about epigenetics…?”
What about it, indeed.
In its simplest sense, epigenetics is the science of how genes get turned on and off. All the cells in your body (more or less) have the same set of 20,000-or-so genes. This is your genome – a set of biological recipes that your cells use to make the molecules that keep them functioning and keep you alive.
But all your cells are not the same, so all the genes can’t be switched on all the time. Otherwise you’d look like some hideous blob of Silly Putty, and that would be awful.
The nerve cells in your brain are using genes that make neurotransmitters and the receptors that receive them, while your liver cells are busy making digestive enzymes to break down your dinner.
And cells also need to respond to changes in the world around them, keeping your body healthy and stable under different conditions, as well as switching myriad genes on or off at the right time and in the right place to direct your growth from a single fertilised egg into a human being.
The genetic instructions remain the same in every cell, but this additional layer of control - over and above the As, Cs, Ts and Gs of the basic DNA code - is known as ‘epigenetic regulation’.
Epigenetic changes within our cells act as a kind of ‘memory’, enabling them to remember what they’ve been told and what they’re doing - so a brain cell doesn’t suddenly decide to stop transmitting nerve signals and start making digestive enzymes, for example.
Some people think that these kinds of memories might not be restricted to the life of a single cell, but can be passed on as cells - or even whole organisms - reproduce. And it’s this concept that has leaked into newspapers, seeped into medicine, and got its fingers into scientific fields from psychology to sociology.
There is breathless reporting of the burgeoning ‘epigenetics revolution’, exhorting us to pimp our genomes by drinking green tea or munching broccoli. In fact, it seems to me to be increasingly used in the same way that non-experts bandy about the term quantum when talking about physics, as a hand-waving non-explanation for mysterious things.
“Why is this child fatter/thinner/taller/cleverer/sicker than their parents?” Epigenetics!
“Why did this normal cell grow into a cancer?” Epigenetics!!
“Why am I addicted to chocolate?” Epigenetics!!!
So what’s it all about?
Read the rest of this story in Little Atoms - click here to read the full version for free.
Meet the Mickey Mouse Mice
You can read the full story of Minoo and her Mickey Mouse Mice - plus plenty more tales from the world of genes and genomes - in my first book, Herding Hemingway’s Cats, available from all good (and evil) bookshops
Amazon (aff): Kindle, paperback
That’s all for now. Next time, we’ll be exploring why some people are more susceptible to diseases than others - yes, including COVID-19 - and whether the answer lies in our genes.
You can find us on Twitter @geneticsunzip and please do take a moment to rate and review us on Apple podcasts - it really makes a difference and helps more people discover the show.
Genetics Unzipped is written and presented by Kat Arney with additional scripting and research by Emily Nordvang. It is produced by First Create the Media for The Genetics Society - one of the oldest learned societies in the world dedicated to supporting and promoting the research, teaching and application of genetics. You can find out more and apply to join at genetics.org.uk
Our theme music was composed by Dan Pollard, and the logo was designed by James Mayall, and production was by Hannah Varrall. Thanks for listening, and until next time, goodbye.
All music and sound effects licensed from Envato or Epidemic Sound.
