Computational, evolutionary and human genomics at Stanford

Feature Interview: María Ávila-Arcos

María Ávila-Arcos is an Assistant Professor at the International Laboratory for Human Genome Research at the Universidad Nacional Autónoma de México/ National Autonomous University of Mexico). She was a postdoctoral researcher in the Bustamante Lab at Stanford University from February 2014 to September 2015, where she studied population genomics and global health. Before that, she studied in Denmark as a PhD student and then as a postdoc at the University of Copenhagen. She received her PhD in Paleogenomics in 2013.

This content is transcribed from an interview that took place on Stanford University campus with CEHG Director of Programs, Cody Montana Sam, and Communications and Outreach Manager, Katie M. Kanagawa. 

AfroMexico Project Description: In January 2015, a fieldwork team led by Ávila-Arcos, a CEHG postdoctoral fellow at the time, collected eighty samples from individuals living in Afro-Mexican villages in the Pacific coastal State of Oaxaca. In a pilot effort, saliva samples were collected, along with genealogical information, anthropometric and skin pigmentation measurements. Given the initial sampling success and the scaling feasibility, this effort has been expanded to analyze the genetic structure of Afro-Mexicans across the Atlantic-Pacific corridor. Mexico’s African roots have importantly impacted the current shape of the population, but they have yet to be represented in modern genomic surveys of genetic variation. The knowledge generated in this study will help characterize this important, yet neglected, third ancestry of Mexicans and will shed light on the genetic dynamics and implications of the slave trade in the Americas.

Why don’t you tell us a little bit about yourself, in the broadest sense? 

I grew up in Mexico City and I went to college in Cuernavaca, a town about 1.5 hours away. Since very young, when I was 18, I jumped straight into genomics and research. The National Autonomous University of Mexico’s (UNAM’s) campus in Cuernavaca hosts the Biotechnology and Genomic Sciences Institutes, and I was part of a very specialized, unique undergraduate program in genomics. It was kind of a pilot project with a reduced number of students and very good, research-driven work. It was apparently successful because most of us who graduated from that program found PhD or Masters degree positions abroad.

Can you talk about the intersection of medicine and genetics in your research? 

28431763894_a9e7fb95ce_o

I’m just starting now to get into that. Right now, I’m very interested in understanding the genetic structure of populations that haven’t been very well characterized from a genetics perspective, admixed populations in Mexico for example. First, you need to understand their genetics, how admixture is structuring them, and then you start to do more clinical studies on them, using this background. So it’s very basic research and then you build on it.

Since you got started in genetics, do you think the field has changed much? How so?

It was a dramatic change. Towards the end of my undergraduate program, I had to write a thesis and, in the last classes I took, I started to hear we had new sequencing machines and pyrosequencing, and there was this idea like things were happening. But then I started my PhD and the next-generation sequencing machines started this massive revolution in genomics and genetics research. So I knew nothing about how to handle this kind of data when I was an undergrad, because it was brand new. I had to learn that as a PhD student, and I had to teach myself these new programs, these new ways of handling massive amounts of data. That was a big change.

One thing we have seen, at least from your awesome lab meeting presentations, is how much you like doing fieldwork, and also making sure that community members are involved in the fieldwork and understand the research. So can you speak a little bit about that? 

Sure. Well I grew up with my dad being an epidemiologist; he did a lot of fieldwork and he would take me when I was a kid into the field. And his research focuses on children. In Mexico, we have a lot of malnutrition and basically his fieldwork involved weighing kids and giving advice to the families on how to better feed their kids. So I was part of that. I grew up doing this fieldwork with my dad, and then I went to school and I never thought I would go back to fieldwork again, but that image of him and also how involved he was with the community and how much respect he had for the community, is something that stayed with me.

And also something very important: when I came here to Stanford and I went to do fieldwork in South America with Karla Sandoval Mendoza [former Bustamante Lab member]. Her background is Anthropology and she also has a lot of experience doing fieldwork in the frame of genetics, so seeing her was really cool and seeing that we share a lot of the same philosophy on how to approach communities and talk to them. That was also something I learned from her.

So tell us about the communities where your fieldwork was located? 

South America was the most exciting. It was my first time doing fieldwork, collecting samples for genetic studies. So I went to Easter Island with Andres Moreno Estrada [Bustamante Lab alumnus] and it was really cool, because it was the second time he was visiting and he was giving results back to the community, so the effect it had on people, to get their ancestry results back, and also collecting new samples for new studies was very exciting. And I went to one community with Karla in Peru; it’s called Magdalena da Cao and we also collected samples there. More recently, I’ve been doing more fieldwork in Mexico with the AfroMexico project.

Does a particular person you’ve met while doing fieldwork, one of the community members, come to mind? And why? 

Yeah, definitely in Oaxaca, Mexico, there is Lucia Mariche, in the context of the AfroMexico project. She lives in Chacahua, an AfroMexican community, and she’s a community leader. Just being able to be in contact with her: she’s really proactive and you can see her leadership when you see her. And she’s also very nice and she was very collaborative. Basically, she was the one who opened the doors for us, to the other communities we visited. So people everywhere we went were like, “Lucy, how are you doing? How is your mom? How is your family?” She was great. She is my favorite person.

If you were to give advice to other people who are interested in doing fieldwork, who maybe don’t know how to get started with these communities, what would you say

29019588056_c256070f88_o

The first advice is you have to build or join a network that is already in place in these communities. You have to find your way through this network first to find a person who is in contact with another person, who is also in contact with another person, etc. So you just need to find that key person and then you’re part of that network, so that people in the communities will know you as part of that network and they will be more open to participating in your study.

Can you tell us a bit more about the AfroMexico project? 

Yeah, sure, that’s my favorite topic (laughs). My interest is characterizing the genetic makeup of AfroMexicans and the reason I am very interested in this is a nice story: while I was doing my PhD and I was more specialized in paleogenomics (ancient DNA), we got these samples from the Caribbean that were from the 16th century. We knew the people were born in Africa, but their remains were found in the Caribbean. Basically, the questions we had with these three ancient samples was: where were these people born? Where are they from? Because we knew, by the historical context, that they were probably brought to the Caribbean by the Transatlantic Slave Trade, and we wanted to know exactly where in Africa they were from.

In the study of the Transatlantic Slave Trade, the question of origins is a very important one and a central one. Because during the Trade, the place of origin–the geographic or ethnic origin–was erased from the records, or not even erased, but not even written or put in the record. Many people don’t have the tools to trace their actual ancestry because the record didn’t include them. So I had that question in mind, and that got me to think a lot about the slave trade in the Americas, and I started to read about the slave trade in Mexico, and the more I read, the more surprised I became, because it’s something you don’t hear much about in Mexico.

But just looking at the history, I realized that there was a lot of trade into Mexico from Africa. As I read more, I found that there are some places in Mexico where you see a higher concentration of people of African descent. So I wanted to see them and work with them because I had the same question: where did these people, their ancestors, come from and when were they brought from Africa to Mexico? That’s how I got interested. I called Carlos [Bustamante] and asked, “Carlos, can I go to collect samples?” And we had the IRB in place. The first time I went was this January. Many months in advance, I started emailing people and getting necessary contacts, so that by the time I got there, people were already waiting for me.

When you go to these communities, how do they themselves identify? 

29052587805_eaf603a0a0_o

It’s becoming more political right now, because these people are fighting for recognition as people of African descent and a vulnerable minority as well. In Mexico, if you speak an indigenous language, then you have access to certain benefits, like scholarships or programs that support communities. But if you can’t identify as Afro-Mexican, because there is no box to check, you are also vulnerable. So if you ask people who are part of this initiative, they would say “yes, I am Afro-Mexican,” but if you ask people who are not, they would say “no, I’m Mexican, that’s just the color of my skin.” But for many people, there is a disconnect between the way they look and the slave trade many centuries ago. They don’t recognize themselves as being from Africa; they see no connection.

In the last fieldwork I did, I asked the question, “how do you self-identify?” In Oaxaca, for example, people are more politicized because there are more movements there for recognition, but in Veracruz, almost no one recognizes themselves as Moreno, or Negra, or Afro-Mexican. Very few people, so it’s interesting.

That’s interesting because there are also those types of discussion within the American black community, as to how you identify and how much you identify with the African continent. If you were to compare and contrast slave routes and the slave trade in America vs. Central America and Mexico, how would you describe it?

It’s very different, and I think that’s one of the important reasons why we need to study Afro-Mexicans, because it just has a different history. We were a Spanish colony and, as a Spanish colony, the deals they were putting in place were different than the British colonies. So, for example, the Spanish bought from the Portuguese and the Portuguese had many of their shipment stations in Angola and Mozambique and most of the people they kidnapped and traded were from those two regions. In America, the British took them from different places along the African West Coast that changed with time, So it’s a different history. It’s been studied a lot among African-Americans, but it’s a different history. You wouldn’t expect the ancestry to be the same. So that’s an argument too.

Have you begun to think about the clinical implications of studying these populations? And have you talked to them about why so many people have high blood pressure, diabetes, and those sorts of issues?

Yeah, so there are two aspects. One reason I got interested is because I started hearing, by talking to people and reading, that there’s a lot of anemia in these places. So that is something that I want to know and I can learn from genetics: if this anemia is a predisposition. The sickle cell anemia, it’s protective against malaria and if you have mild anemia, you’re protected against getting malaria. I was curious to hear if the anemia that’s been observed in these regions could be related to sickle cell, as opposed to just not having good food with enough iron. So that was the first clinical aspect that I wanted to address.

And then I am also very interested in the skin pigmentation piece. When I was there, I collected the skin pigmentation data, because that also has implications on certain things, like predispositions for skin cancer (because the color of your skin determines how much UV you filter, and also if you are more or less likely to get skin cancer). So that’s another aspect I’m researching.

What are the clinics like in the communities you visited, and how do you interact with clinicians and doctors?

29019587416_b2d20cf97f_o

There are not many there. Like in Oaxaca, for example, many people saw us and thought we were medical doctors and they would come and say, “I have this pain here,” “I feel bad in the mornings.” They wanted advice on their health and we had to say, “No sir, we can’t.” But there is very poor health there, and that was pretty sad to see.

Also, in the second fieldwork I did, there was a breakout of the chikungunya virus and that was really bad. In Oaxaca, some people had it, but in Guerrero, almost everyone had it. It’s a virus that is transmitted by a mosquito, so many people were sick and that’s a very painful disease. It’s like a very bad flu, but with a lot of joint pain and rashes. Many people came to us and said they had it, or they had had it recently and they were still in pain. I wished I could something about that, and that was a bit frustrating.

But then in Veracruz, we were super lucky to have on our team a medical doctor, Cesar, who came with us. That was great because, as we were measuring the hemoglobin, whenever we would find a low value we would ask Cesar to talk to these people and give them some advice. The people who came to us with pain, we could direct to Cesar and that was less frustrating than in Guerrero. And people really appreciated having someone to talk to about how they feel, because they don’t normally have much access to healthcare services.

So even though you’re not technically a clinician, are you able to give results back to the communities, say about a predisposition, and direct them to a doctor or anything like that? Can you do any amount of genetic counseling when you are out in the field?

I don’t think I would, at this stage, because they are admixed populations and most of the association studies are not based on people with African or indigenous ancestry. They are mostly done on people with white ancestry. And then in terms of monogenic diseases, I couldn’t feel comfortable giving those kinds of results.

29052587975_45a7b856d7_o

But what I can do and what they really liked is when we were measuring hemoglobin with a portable device and we were giving their results back to them that minute. So we would take a droplet of blood and measure their hemoglobin and say you’re ok or you’re low. And we would gather the people with low values and give a talk about what they can do to increase their levels. In Oaxaca, we had Silvia, a nutritionist who lives in the area, with us. So she could tell them what food sources found in the area are good for them. In Veracruz, Cesar could tell people what they can do, and for overweight people, why that can be dangerous. But that is the extent of the clinical advice that I feel comfortable giving.

So what’s next for you?

I’m flying to Mexico in a few hours (laughs). I’m starting a new position in Mexico, and it’s the National Autonomous University, the same university where I did my undergraduate studies. I’m excited! I know it’s going to be very challenging; it’s not going to be easy, because science policy in Mexico is very different than in the States or in Denmark, where I did my PhD. There are less resources, there’s a lot more bureaucracy, we have to do a lot ourselves, and you have to secure your own funding starting on day one. That’s going to be challenging, but I also like the idea of being closer to my fieldwork, and interacting with other Mexican scientists who are there (like Karla and Andres).

Are you excited about mentoring other grad students and postdocs who are coming up in Mexico?

Yes, definitely. I like teaching and I like to give advice to people, especially Mexicans who may be afraid of going abroad. I would basically like to have people from this community doing research on themselves.

What do you see as the role of Stanford CEHG, moving forward?

I really like CEHG. They have been super supportive of my projects. I think that the role of CEHG is just making our lives easier by giving us resources to fund our research, and giving us every tool we need to do our job, which is doing research, and not worrying about anything else.