The arms race between pathogens and their hosts leaves clear genetic marks: the most quickly evolving parts of host genomes often include immune genes. But are these fast-movers the exception among immune genes, or do most genes in this class bear the genetic signature of strong selection? In the January issue of GENETICS, Early et al. address this question.
In their comparison of five Drosophila melanogaster populations using information from FlyBase (a database of information on fly genes and genomes) and genetic data from a recently sequenced set of Drosophila lines called the Global Diversity Lines, the researchers found that viral defense genes are evolving at a remarkably fast pace. Genes that protect against viruses through the RNA interference pathway, which involves using RNA to shut down pathogens’ gene expression or translation, showed particularly elevated rates of change.
The evolution of genes responsible for resisting bacterial and fungal invaders, in contrast, is much more sluggish. And the changes are not as far-reaching—rather than broadly altering the regulation of the immune response, the adaptations to bacterial and fungal threats tend to involve making minor tweaks to recognition and effector genes.
Early et al. also found that some types of immune genes have changed more rapidly at the population level than at the species level and vice versa. For instance, phagocytosis and recognition receptor genes showed signs of rapid adaptation at the population level but not the species level, while genes in the Toll and immune deficiency (IMD) pathways had the opposite pattern.
This discrepancy may have been found because the population data came from samples collected at one specific time and thus can’t capture the dynamic fluctuations in selection and adaptation over a longer period. The fact that the researchers observed significant alterations to viral defense genes at both the population and species level, then, is a testament to the powerful directional selection driving those changes.
These extreme cases may lead to the impression that immune system genes in general are evolving more rapidly than the rest—a view that, the researchers conclude, doesn’t capture the whole story, at least in the fruit fly.
CITATION:
Early, A.; Arguello, R.; Cardoso-Moreira, M.; Gottipati, S.; Grenier, J.; Clark, A. Survey of Global Genetic Diversity Within the Drosophila Immune System.
GENETICS, 205(1), 353-366.
DOI: 10.1534/genetics.116.195016
http://www.genetics.org/content/205/1/353
Nicole Haloupek is a freelance science writer and a recent graduate of UC Berkeley's molecular and cell biology PhD program.
View all posts by Nicole Haloupek »Read more in
-
Early Career Leadership Spotlight: Julio Molina Pineda
We’re taking time to get to know the members of the GSA’s Early Career Scientist Committees. Join us to learn more about our early career scientist advocates. Julio Molina Pineda Policy and Advocacy University of Arkansas Research Interest My research interests focus on using model organisms to genetically dissect complex traits related to human disease. My…
-
Early Career Leadership Spotlight: Peiwei Chen
We’re taking time to get to know the members of the GSA’s Early Career Scientist Committees. Join us to learn more about our early career scientist advocates. Peiwei Chen Accessibility Subcommittee California Institute of Technology Research Interest Far from a harmonious place, the genome is a battleground, where every bit of DNA fights for inheritance and…
-
#Dros23 GSA Poster Award winners
We are pleased to announce the GSA Poster Award winners from the 64th Annual Drosophila Research Conference! Undergraduate and graduate student members of the GSA were eligible for the awards, and a hard-working team of postdocs volunteered their time as judges. Congratulations to all! Undergraduate Students 1st Place: Sofia Karter Lopez, University of Toronto “Rab11 mediates E-cadherin recycling during…
-
Congratulations to the Fall 2022 DeLill Nasser Awardees!
GSA is pleased to announce the recipients of the DeLill Nasser Award for Professional Development in Genetics for Fall 2022! Given twice a year to graduate students and postdoctoral researchers, DeLill Nasser Awards support attendance at meetings and laboratory courses. The award is named in honor of DeLill Nasser, a long-time GSA supporter and National Science Foundation…
-
New editors join GENETICS, G3 editorial boards
Several new editors are joining the GSA Journals. We’re excited to welcome Ricardo Zayas to the GENETICS editorial board under the Molecular Genetics of Development section, and on the G3: Genes|Genomes|Genetics board, we welcome Polly Campbell, Kevin Vogel, Joe Parker, and Ricardo Mallarino. Ricardo Zayas Associate Editor Ricardo Zayas is a Professor of Biology at…
-
Worms and Flies Provide Key Clues to Medical Mystery
This article is part of a series of posts outlining the history and impact of research in experimental organisms. The series is developed in collaboration with the GSA Public Communications and Engagement Committee. By the time Bertrand Might was six months old, it was clear something was amiss. His muscles weren’t developing normally; he was…
-
Congratulations to the 2023 Early Career Leadership Program Cohort!
The Genetics Society of America (GSA) is excited to announce the latest cohort of student, postdoc, and early-career research leaders joining the Early Career Leadership Program. Participants receive training and mentoring while serving on committees charged with understanding the needs, interests, concerns, and challenges of early career scientist members of the GSA. As part of…
-
GSA LOCI: Local Outreach Community Initiatives @ GSA Conferences
Highlights: Local Outreach Community Initiatives (LOCI): The Genetics Society of America is committed to supporting the communities of the host cities of our conferences. This new year, we are excited to reconnect with our GSA community in meaningful ways within and beyond our existing programming. The GSA membership has created a caring and supportive environment…
-
New members of the GSA Board of Directors: 2023–2025
We are pleased to announce the election of five new leaders to the GSA Board of Directors: 2023 Vice President/2024 President Mariana Wolfner Distinguished Professor of Molecular Biology and Genetics and Stephen H. Weiss Presidential Fellow My research has focused on the genes and pathways that mediate sexual development and reproduction, primarily in Drosophila. From…
-
Lance David Miller: Lighting Your Own Fire by Finding the Right Resources
By Daniel J. Gironda In the Paths to Science Policy series, we talk to individuals who have a passion for science policy and are active in advocacy through their various roles and careers. The series aims to inform and guide early career scientists interested in science policy. This series is brought to you by the…
-
Graça Almeida-Porada: The Importance of Communication in a Technologically Advancing World
By Daniel J. Gironda In the Paths to Science Policy series, we talk to individuals who have a passion for science policy and are active in advocacy through their various roles and careers. The series aims to inform and guide early career scientists interested in science policy. This series is brought to you by the…