Gins & Genes: Oh, you're a mutant!

14 August 2019

Interview with 

Alexis Braun & Eva Higginbotham, University of Cambridge; Patrick Short, Sano Genetics

GIN and TONIC

A glass of gin and tonic

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It’s time for Gins & Genes - a brand new segment hosted by the Cambridge Distillery. Phil Sansom assembled three genetics experts to sample some gin and ask them some of the burning questions that are left over from the episode. This week’s panel is Alexis Braun, Eva Higginbotham, and Patrick Short…

Patrick - Hi, I'm Patrick, I'm a researcher in rare diseases and CEO of a startup company called Sano Genetics.

Alexis - Hi, I'm Alexis, I'm a postdoctoral researcher in the Department of Genetics with the University of Cambridge.

Eva - I'm Eva and I'm a PhD student at the Department of Zoology in Cambridge.

Phil - So welcome to the first ever Gins & Genes here at the Cambridge Distillery. Will Lowe who runs the distillery is here to tell us: what gin are we going to try?

Will - Well we're gonna start off with Cambridge Dry Gin. It’s the flagship of Cambridge Distillery. We have a unique method of distillation which means we take each botanical individually and we distil them at different temperatures to preserve the freshness. So everything that's in this gin, the recipe, originally was actually grown in my own back garden.

Phil - Cheers everyone.

In this episode we've been talking about Gregor Mendel, right. Gregor Mendel spent eight years rubbing bits of flowers onto each other. Is that at all similar to the way genetics looks today?

Alexis - We do in a way do similar things. We will pick a specific animal, mate it to another one, probably have to go through lots of different crossing just to try and get to a point where we can answer our questions.

Eva - Thinking about it, the life of someone who works with flies is so similar to those eight years of Mendel rubbing together bits of plants. I mean, we spend a lot of time moving flies around on these little plates that are infused with carbon dioxide so they fall asleep and don't just fly away. And you move them around with a paintbrush, and you sort them, and so you collect the flies you want to then mate with other flies, and it's a lot of choosing the right ones to mate with the other ones. It's just having it put in that way I find...

Phil - Is it reductionist?

Eva - No, it really resonates actually. Just because the life of a geneticist can look like, I'm doing really fancy science, I’m going to use a fancy machine, I'm going to extract some DNA, I’m going to extract some of this and that. But also the life of a geneticist is looking at flies under a microscope and choosing the best boy and the best girl, and putting them together in a tube.

Phil - Some people say that when it comes to the way that genetics gets taught... it always starts with Mendel, but some people say that teaching should, I don't know, be revamped - because we know so much now about the way your environment changes you. What do you guys think?

Alexis - I strongly disagree. You have to start with the basics, and it can expand into more complicated things. But I think you would never start with calculus; you would teach basic arithmetic first.

Patrick - To your point though, I would say, sometimes it takes us a long time to unlearn these things. I worked on rare disorders in my PhD which are often described as Mendelian, which means it's caused by a single gene, or a single mutation in a single gene, or two inherited variants. The thing that we're relearning now is that actually, even in some of the most clear-cut Mendelian cases where you have a single gene that's hit, it's modified by your environment, it's modified by other genetic variants. And there are also cases where people have the mutation that you'd suspect would cause a disease, but they don't have it.

So there's clearly other things going on. And sometimes it takes us as scientists a long time to unlearn the many decades of, “this is how things work,” and then you have to occasionally revise your thinking to incorporate new knowledge. But I would still say I agree that if you start with, “it's really complicated, genetics, environment, it can be every gene, it can be one gene,” then the kids are going to probably just say, “I'm out of here and I'll be watching YouTube instead.”

Eva - Generally I agree that we want to start kids off in a way that seems relatable and understandable when it comes to genetics, and hype up the interest. And one way teachers try and do that often is to try and find specific things about the student.
So for example everyone's heard of the eye color. You know, brown eyes are dominant over blue, green are a bit weird. And I actually have, one of my eyes is half brown. And I remember being in Year Seven in science and we learnt that brown eyes are dominant, blah blah blah. And I said to the teacher, “what about me, one of my eyes is half brown?” And she said, “oh, you're a mutant!” And I quite liked that because I liked science, that was fine with me. But at the same time it's also really hugely inaccurate.

So I think what Patrick’s saying about “takes time to unlearn things” is really valid. And actually I was looking through some myths of human genetics. So the one that really surprised me is that apparently some kids were taught that the direction that you cross your arms is dependent on your genetics. If you just cross your arms now, you guys. Okay, so Patrick has his right arm on top. Alexis, oh, she has her left arm on top. Now some kids were taught that if you put your right arm on top that's a dominant trait, but if you put your left arm on top that's a recessive trait. Which is just... it's just incredibly wrong! I mean, that kind of... it's unbelievably wrong. I was just so amazed.

But it turns out that there is one really great example of something that really does follow the rules of Mendelian inheritance, and that is earwax. I know, I know, it's gross. And there are actually two types. And which type you have is really largely dependent on which geographical part of the world your ancestors came from.

So if you’re ancestrally from parts of Europe or from Africa, or a few other places, then you likely have wet earwax, which means that it ranges from yellow to brown and it's wet. Now if you are from most of Asia - in particular Southern Asia - then it's likely that you have dry earwax, which means that it's sort of grayish in color and crumbly. I'd never heard of this before I saw this example.

And it's actually really true that it's dependent on one base pair change, from a G to an A. And if you have a G you make wet and if you have an A you make dry. So in some ways that's kind of like the best... it's a pure example that you could use to teach children - if you wanted them to be playing with earwax in the classroom - about this Mendelian inheritance.

But I do think it's true that we need to be careful that we don't go around telling kids, “oh, how you cross your arms, what color your eyes are, whether your earlobes are attached, whether you have a widow's peak, whether you have a hair whorl…” I mean the list is amazing, and that should probably be... we should pull back on that I think.

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