Space genes! Bloody space genes!
If you’ve been keeping an eye on popular science news recently, you’ve probably come across the story of a comparative study between current astronaut Scott Kelly and his retired astronaut brother, Mark. Along with this came the breathless headlines, tweets and shares on how 7% of Scott’s DNA had changed after his time in space! They weren’t identical twins anymore!
Which is insane!
The media ran riot with the idea that massive changes had occurred between the sequences of the two men’s genes – which wasn’t the case at all. Seven percent would be an insane level of divergence.
What was actually detected was a change in gene expression – changes in the level of a gene product being made, not the gene sequence itself. Which is an entirely expected result really – an organism has to be dynamic in order to adapt to different environments. And space is a pretty unusual environment for a human to find themselves in.
Media coverage of genetics and genes is often poor and prone to hype, and public misconceptions can be really persistent. This is where Herding Hemingway’s Cats, Kat Arney’s book on genes and gene expression, really has a chance to shine.
Dr Kat Arney is a science writer and communicator who has a background in epigenetics. This makes her very well suited to explaining concepts in genetics that are commonly misunderstood. She does this in an easy, casual manner, littering her chapters with colourful analogies and footnotes. The book is immediately open and welcoming to a non-expert in a way most textbooks are not. She also skillfully handles the balance between showing enthusiasm for a new subject and getting carried away on the hype train. She admits that she’s drawn to curmudgeons and sceptics, and the caution that comes with it is perhaps something more people should emulate.
I was quite impressed with what was covered in the twenty-two chapters. Most of these chapters focused on one particular topic or issue in genetics, accompanied by an interview with a scientist involved in that field. Some of these are absolutely fantastic. My personal favourites include those of Mark Ptashne and Wendy Bickmore. (Poor Wendy seemed a bit thrown off balance with the mention of ‘Bickmore’s Balls.’) I love that we get to see the scientists themselves explain their own work, and I love how Kat’s descriptions of them show us just how human they are, with their own quirks and eccentricities.
So how do the Hemingway’s Cats of the title fit into all this? Is it some kind of attempt to span C.P. Snow’s Two Cultures using the power of cute kitty pics? Not quite, although this isn’t going to stop me from dotting the rest of this review with cat pictures.
Ernst Hemingway was a cat lover and supposedly had an inordinate fondness for polydactyl cats – cats with six toes on each paw instead of five. This trait gives their paws a distinct paddle shape. Kat’s interview with geneticist Bob Hill shed some light on the mystery of the genetic basis of these kitten’s mittens, and it’s linked to the regulation of a gene called Shh – Sonic Hedgehog. Sonic Hedgehog is involved in pattern formation – the mechanism where cells in a developing embryo start to take on different roles and forms. It’s not a change to the protein itself that causes the extra digit on the cat’s paws – but changes in the ‘control switch’ that determines when, where and how much the gene is expressed. It turns out to be a less than straight-forward story, and a great example of how real life biology can be a little messy.
And as to why that gene is named after a video-game character? That’s also explained in the book.*
I listened to the audio version of this book, which Kat does a fantastic job narrating. It’s a very easy listen. She also does little impersonations of each of the people she’s interviewed, which can be quite entertaining, although I have to wonder what the interviewees think of them. (My favourite is Dan Graur’s.) But there is a drawback to the audio version of the book – there is no easily accessible glossary or reference list for anyone tripping up on the terminology or hoping to do any further reading.
So if you want a better understanding of the basics of genes and gene function, and you don’t have a background in biology, I would really recommend giving Herding Hemingway’s Cats a whirl.
And get a heads up before the next space genes fiasco!
* While I’ll keep the origin of the gene name a mystery for those who would like to read the book, I will point out that any time you see a gene with a ridiculous or almost inappropriate name, the guilty party is almost always a fruit fly researcher. Because we are terrible.
My favourite includes someone naming a gene linked to the development of epilepsy julius seizure. I don’t know how they got away with that.
Reference on the Kellys: https://www.nature.com/news/astronaut-twin-study-hints-at-stress-of-space-travel-1.21380