Inside AJHG: A Chat with Lluis Quintana-Murci

Posted By: Sara Cullinan, PhD, Deputy Editor, AJHG

Each month, the editors of The American Journal of Human Genetics interview an author of a recently published paper. This month we check in with Lluis Quintana-Murci (@quintanamurci) to discuss his paper “Impact and Evolutionary Determinants of Neanderthal Introgression on Transcriptional and Post-Transcriptional Regulation.”

Lluis Quintana-Murci
Lluis Quintana-Murci (far right) with the members of his lab, including Martin Silvert and Maxime Rotival (courtesy Dr. Quintana-Murci)

AJHG: What prompted you to start working on this project? 

Lluis: My laboratory is interested in the evolution of human populations and their long-standing relationship with infectious agents; half of the lab thus works on population genetics questions and the other half focuses more on population/systems immunology. In the context of this project, it all started back in 2016, when we found that Neanderthal introgression has affected innate immunity genes as a whole, and that some innate immunity genes (e.g., the TLR1/6/10 cluster) display extremely high levels of Neanderthal ancestry (Deschamps et al. Am J Hum Genet, 2016).

Later that year, we also found that Neanderthal introgression has been pervasive among regulatory variants (eQTLs), in particular those involved in responses to viral stimuli including influenza (Quach et al. Cell, 2016). The next natural question was then to explore how Neanderthal-introgressed variants in the genomes of non-Africans have affected more generally transcriptional and post-transcriptional regulation, focusing on promoters, enhances and miRNA-mediated regulation, in different tissues and cell types.

AJHG: What about this paper/project most excites you? 

Lluis: Several things. First, although Neanderthal introgression has had relatively little effect on miRNA-mediated regulation, a mechanism that in general tolerates little variation and is highly evolutionary constrained, a few Neanderthal variants in a few miRNAs can exert a massive impact on downstream transcriptional programs. In general, I am fascinated by the fine-tuned “smart” way miRNAs function.

Second, I am excited about our results of enhancers, in particular the enrichment in Neanderthal ancestry we find in enhancers that are active in T cells (yes, sorry, I have a biased interest in all immune-related processes). What is even more interesting is that the excess of Neanderthal ancestry we observe in T cell enhancers is not due to increased Neanderthal introgression. Instead, it results from a higher human-Neanderthal divergence at these elements. This may reflect past adaptation in the Neanderthal lineage for this type of enhancers.

AJHG: Thinking about the bigger picture, what implications do you see from this work for the larger human genetics community?

Lluis: This work highlights once more the potential benefits of admixture between our ancestors and other human forms, such as Neanderthals or Denisovans. The latter were adapted to their environments, whereas our ancestors entering Europe or Asia were less adapted. In this context, acquiring advantageous variation through archaic admixture is a fascinating topic, with obvious consequences for the larger human genetics community. Indeed, such archaic admixture increasingly is being shown to affect molecular phenotypes such as gene expression or mechanisms of gene regulation (e.g., this study) and more generally, organismal phenotypes such as traits and diseases (e.g., skin pigmentation, sleeping patterns, allergies) in present-day human populations.

AJHG: What advice do you have for trainees/young scientists?

Lluis: Be open while doing research, be curious, be rigorous, exchange a lot with other trainees and PIs, read a lot, and MAINLY, have fun and be passionate! Meaning both in your working and non-working life. Enjoy the work, do not suffer from it! For me, this is rule number one. If you follow this rule, great findings will follow…and, yes, a bit of luck also helps.

AJHG: And for fun, tell us something about your life outside of the lab.

Lluis: I like to garden (actually, I can spend hours gardening), to bike, and, increasingly, to run. These three things really empty my mind and recharge my batteries. Also, I do need to go at least once per year to Mallorca (where I was born). Having lived there until I was 20 gave me a handicap for life: my need for sun and sea (and I live in Paris…). There’s nothing that relaxes me more than getting into the turquoise Mediterranean water and swimming!

I also love art exhibitions, almost exclusively modern art, and pop if possible! I spent last summer in NYC on a mini-sabbatical at Rockefeller University, and I really enjoyed the exhibitions there!

I also like to read. I can compulsively read historical biographies. When I enjoy somebody’s life, I can read 30 books about them even if most of them say the same thing. A recent example is the life of Princess Marie Bonaparte – a psychoanalyst and close friend of Sigmund Freud, whom she helped escape from Nazi Germany. I also love reading about contemporary politics: one of my preferred topics is the so-called “Spanish transition,” the period starting 1975-1980 when Spain transitioned from being under Franco’s non-democratic regime to being the modern, open-minded country that is today. Obviously, I like books about evolution, but then, that is more work-related again…

Lluis Quintana-Murci, PhD, heads the Unit of Human Evolutionary Genetics in the Department of Genomes and Genetics at the Institute Pasteur. He is a first year member of ASHG.

Inside AJHG: A Chat with Janet Kelso

Posted By: Sarah Ratzel, PhD, Science Editor, AJHG

Each month, the editors of The American Journal of Human Genetics interview an author(s) of a recently published paper. This month, we check in with Janet Kelso, to discuss the paper, “The Contribution of Neanderthals to Phenotypic Variation in Modern Humans.”

20171010_AJHG-Neanderthals
A Neanderthal scene re-created by research group members. (courtesy Dr. Kelso)

AJHG: How did you begin working on this project? 

Janet: We previously studied regions of the genome where there is evidence for Neanderthal DNA in the genomes of present day non-Africans and had inferred, based on the functions of genes nearby to these Neanderthal segments, the influence of Neanderthal DNA by looking at predicted gene functions and at changes in gene expression.

However, directly identifying associations between Neanderthal DNA and phenotypes requires access to large datasets that provide both genetic information as well as well-characterized phenotypes in very large numbers of people. Such datasets were not available until quite recently. In 2016, a study from the Capra group looked specifically at the influence of Neanderthal alleles on disease phenotypes by using medical records for over 25,000 people. They identified a number of really interesting associations between Neanderthal DNA and disease risk. We were interested in extending this idea to include non-disease phenotypes in order to determine what influence Neanderthal DNA might have on ordinary variation in people today.

Because Neanderthal alleles are rather rare in people today, we need to have a really large number of people. The UK Biobank pilot study now provides such an extensive resource, including genetic information as well as information about hundreds of common phenotypes in more than 100,000 individuals. Therefore, we were finally able to investigate the impact of Neanderthal alleles on common phenotypes in modern humans.

AJHG: What about this paper most excites you? 

Janet: A notable aspect of our study is that the growing move to collect both genotype and phenotype information in biobanks, such as the UK Biobank, now provides us with the ability to answer not only biomedical questions but also to understand the evolutionary history of modern human traits.

We were able to determine directly the effect of Neanderthal DNA on the phenotypes of people today. Our findings are consistent with previous inferences that genes involved in skin and hair biology were strongly influenced by Neanderthal DNA. However, in those previous studies it wasn’t possible to determine what aspect of skin or hair biology was affected. We were able to show that it is skin and hair color and the ease with which one tans that are affected.

It was somewhat surprising that we observe multiple different Neanderthal alleles contributing to skin and hair tones. Some Neanderthal alleles are associated lighter tones and others with darker skin tones, and some with lighter and others with dark hair colors. This may indicate that Neanderthals themselves were variable in these traits.

A number of the phenotypes to which Neanderthal DNA contributes in people today seem to be related to sunlight exposure. For example we see contributions to skin and hair pigmentation, mood, sleeping patterns, and smoking status. It is therefore tempting to speculate that Neanderthal contributions may have been important in our adaptation to a modified sunlight regime during the colonization of Eurasia.

AJHG: Thinking about the bigger picture, what implications do you see from this work for the larger human genetics community?

Janet: Our study is notable in that it shows the enormous benefits provided by biobanks in which both genotype and extensive phenotype information are collected. The use of biobanks in in such studies is relatively new, and demonstrates that resources such as the UK Biobank provide us with the ability to answer not only biomedical questions but also to understand the evolutionary history of modern human traits.

More specifically, we have been able to determine directly the effect of Neanderthal DNA on a very broad range of non-disease phenotypes in people today.

AJHG: What advice do you have for trainees/young scientists?

The growing amount of genetic data from both archaic and modern humans provides a tremendous opportunity for creative people to tackle interesting questions in understanding the evolutionary basis of modern human traits and diseases.

Janet Kelso, PhD, is a computational biologist and Group Leader of the Minerva Research Group for Bioinformatics at the Max Planck Institute for Evolutionary Anthropology.