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Dr Megan Davey on how embryos grow

Why we have five fingers, recreating 250 million years of evolution, Sonic Hedgehog and the wish of being a fiction writer.

Dr Megan Davey engaging with younger audiences.
Dr Megan Davey engaging with younger audiences.

Dr Megan Davey is a developmental biologist at The Roslin Institute. In this interview, she talks with Science Communication Intern Maggie Szymanska about her research to understand how chicken embryos grow and why she followed this career path.

Could you tell me about your work in a nutshell?

I am a developmental biologist, which means I study how embryos grow. Specifically, I study chicken embryos. Chickens are very informative and are a good animal to study, as chickens lay eggs so the embryos are outside the mother. This makes it easier to see what is happening.

In particular, I look at how limbs develop and how patterns are formed. For example, why do we have five fingers, with a thumb on one side and a small pinkie on the other?

This is important as these genes are used everywhere and are used throughout life. If we can begin to understand simple things about fingers, we can use that knowledge to begin to better understand more about other complex parts, like brains and livers.

How did you become interested in this research?

From a very young age I had so many questions about how different parts of our body are made. I remember realising that all of our cells have the same DNA and I would wonder why some of our cells made hair while other cells made eyeballs. One question that was particularly exciting to me was why do we have fingernails on the end of our fingers and not eyeballs? It was a bit of an odd question but it sparked this interest in embryos and development. Questions like that led me to following my interests and I always ended up doing something fascinating.

How do you see the future of your research?

I think this is a very exciting time to be a biologist actually, or a scientist of any sort. There are so many new developments currently occurring in science, there is so much investment, so much public involvement. I think that is all extremely exciting.

For my personal science, CRISPR/Cas9 genome editing is incredibly transformative. It has completely changed our approach to genome editing, how we do things and how quickly it can happen. It gives us so many possibilities, nearly every month there is a new different way we can apply genome editing to look at cells, delete cells, tag proteins and other uses. It’s amazing because we still haven’t figured out all the possibilities. It feels like the world is my oyster.

What are some challenges you have faced?

I think many people think that you can just do science and it works. You go into a lab, you experiment and then you get a “yes” or a “no” answer. A challenge for me was that science is never that straightforward. Most of the time the answer is something completely unexpected. There is a lot of troubleshooting involved and scientists spend a lot of time just trying to get something to work.

From a more personal perspective, another challenge for me is that I find science to be very competitive. That makes me quite anxious and it is not always a very comfortable situation to be in. Some people have a competitive nature and they enjoy that competitive environment, but it is not that inclusive for people who aren’t.  

Do you have a favourite project from your time here at the Institute?

I have to say I love most of the work I do here, picking a specific project is quite difficult. A problem I often face is actually liking too many projects at the same time.

One of the most exciting experiments was proposed to me a few years ago by one of my students. He had an idea that he had come up with himself and despite being doubtful I let him run it. Amazingly, it worked! The idea was looking into why chickens have four toes, despite having five toes millions of years ago. The student had a very simple hypothesis and method, he inserted a tiny bead of protein that he thought was missing into the chicken embryo. The result was that the chicken grew an extra toe! To me that was amazing because he managed to recreate 250 million years of evolution with a single bead of protein. It brought home to me how powerful evolution is and also highlighted how dynamic the embryo is.

Why did you decide to be a scientist?

When I was a schoolgirl I knew I really liked biology, but I also knew I didn’t want to be a doctor.  I decided to study developmental biology as I knew that that was the part of biology that fascinated me the most. I always knew what sort of science I wanted to do, I knew I wanted to look at how embryos grow. Everything progressed very naturally from there. I made a lot of lucky choices but I also made sure not to rush For example I took a break before continuing on with postgraduate research.

How would you say your work influences others?

A lot of our research helps in understanding various human limb congenital differences, such as missing thumbs, extra thumbs or missing bones in the middle of a finger. As a child, it doesn’t affect your survival but it greatly affects your life. This is especially true in humans, as we use our hands so much: it is part of the language, we hold hands, we explore the environment with our hands. Hands are very important and understanding how hands are made is necessary to understand various birth defects.

Additionally, the genes that we use to develop hands are the same genes we use all the time, in different places throughout life. In particular, I look at a gene called “sonic hedgehog”, one of the main players in many cancers. By studying this gene we can improve our understanding of these diseases.

I’m also quite interested in making a difference globally to food production and security. A lot of the work I do looks at differences between chicken breeds, why is one chicken breed skinnier and the other fatter? It is still early days for this research but it is a very useful tool for looking at obesity and diabetes, as we share a lot of the same genes.

If you weren’t a scientist, what would you be?

I think I’d like to do something practical, something that really helps the community. I think a midwife or a nurse would be great options.

Or, being more wishful, I would say be a fiction writer. I have always loved to read and write a lot, taking myself away to another world.

Related links

The function of genes and cellular phenotypes in animal systems

Study reveals genetic changes linked to flat-faced dogs

Gene expression and sex differences