Interview: Efraín Rivera-Serrano

I grew up on a farm in Puerto Rico, growing crops and breeding animals to get specific traits. It wasn’t until later in school that I was introduced to Mendelian genetics and how traits are inherited, which I could link to my passion for farm life. And then I just fell in love with the overall science of life when I was introduced to the concept of cells, and how cell division can create multicellular organisms like humans from just one or two cells.

In 2013, Stanley Lemon’s lab at the University of North Carolina, which I joined in 2017, showed that the hepatitis A virus actually exists in two different forms – the historically known naked form in which the genetic material inside the virus is protected by a protein shell, and a novel quasi-enveloped form (in which a lipid membrane lacking viral-encoded proteins surrounds the protein shell). My project involved understanding why both forms were able to invade liver cells quite efficiently, despite their differences.

After the virus has infected a cell, its protein shell needs to start disassembling so that the genetic material can get to the cytoplasm of the cell and make more copies of itself. I was tasked to see whether we could visualize this disassembly process, and see what happens to the lipid membrane of the quasi-enveloped form of the virus during this process. That was a tricky experiment, because it’s a very dynamic process.

We developed a tool that can label the protein shell and the lipids simultaneously, which allows us to use a microscope to view where and when they come apart. We found that the quasi-enveloped form of the virus goes all the way to the lysosome – the compartment where the cells degrade the material they don’t want. This form of the virus travels further than its naked counterpart, which does not go to the lysosome because it doesn’t have any lipids to be degraded.

My years of research experience have taught me to be very sceptical. I think it was the third time that the experiment worked before I actually believed it! Once we got those results the paper expanded from there. That was probably the best moment of the two years that I was in that lab.

Shortly after we prepared the paper for publication last year, I thought: where do I see myself in the long term? I had been in North Carolina for 10 years and I felt like my whole life needed a change. So I decided to move across the country to California and start a new postdoc. Now, rather than looking at how viruses enter cells, I look at what happens to the genetic material of the virus: what it encodes and where does it go once it’s inside the cell.

The training part is most important to me. I grew up in a family with limited resources, my mom left education after middle school, at about 12 years old, and yet I was given the opportunity to succeed professionally – I got into college and internships in the United States, and then later was accepted to grad school. I’ve always felt like I should give back to people who perhaps will not consider a career in science. So the thing that I enjoy the most about my job is teaching the undergraduate students who rotate in the laboratory what science really means. I want to show that the discoveries they learn about in textbooks came from actual people. I think that gets lost in the classroom.

The high degree of uncertainty. You don't know if your hypothesis is right or wrong, but that ‘a-ha’ moment makes this career what it is. What’s worse is that many of my colleagues in grad school joined laboratories that didn’t know if they were going to have funding in 3–4 years’ time, which restricts the intellectual freedom of the students. It would be better to give trainees more certainty that they’re going to be in the same place for long enough to be curious and to develop themselves as scientists.

I started using Twitter midway through my PhD to get more exposure to fields of biology that I would normally not read about. One thing led to another – I started following people I met at conferences, then started expressing my own opinions. I recommend it to everyone that I meet because science can be very isolating if you do not have the right support system. If I have questions or I need support I can always reach out to my friends on Twitter, even though perhaps we haven’t met in person.

Every time I go to a conference now I know many of the attendees from Twitter, which breaks the ice! I’ve had people message me for help on projects – even if it doesn’t lead to a joint publication that exchange of knowledge is very important. And actually I found the postdoc that I have right now through Twitter. I posted that I was looking for a postdoc in a particular field, and I got 14 offers within a month.

That’s without a doubt my PhD advisor, Barbara Sherry. If it wasn’t for her there’s no way I would be doing science right now. I had interpersonal problems that meant I had to quit my first PhD, and I thought that that was going to be my end as a scientist. Then I met her and she’s probably the best mentor one could ever ask for, and so passionate about science. She helped me navigate through going back to grad school, and gave me the opportunity to rotate in her lab and see if I like working with viruses. I had never taken a virus course in my life – my background was actually botany – but she saw something in me. And here I am still doing viruses!

My ideal career would be 70% teaching and 30% advising, mentoring, and directing undergraduate programs. I want to use research tools and the concept of knowledge discovery, whether in the laboratory or not, to inspire others and get them interested in higher education overall, and also in science as a career.

I love to hike and run; I’m always exercising. I spend a lot of time outdoors with my family: my husband and our five rescue dogs. They’ve moved with me several times thanks to my career in science – when we moved from North Carolina to California we had to drive for five days with a carful of dogs!

I have plenty of tattoos of viruses and other stuff that I’m passionate about in science. I saw a picture of a similar tattoo online last year, and it just hit me that mitosis was really the reason why I studied biology in the first place: the beauty of cell division. As a joke I posted on Twitter that I’ll get the tattoo when I get 5,000 followers – I only had about 1,000 followers at the time so I didn’t think it would happen. It was pretty fun, because I love mitosis, and it really showed me in a four or five month span how much my presence on social media had grown.

2018–present: Postdoctoral scholar, University of California, Davis, USA

2017–2018: Postdoctoral fellow, University of North Carolina at Chapel Hill, USA

2012–2016: PhD in comparative biomedical sciences, North Carolina State University, USA

2009–2012: MSc in plant cell biology, North Carolina State University

2005–2009: BSc in biology and chemistry, Pontifical Catholic University of Puerto Rico