In the 1940s, C. H. Waddington discovered a peculiar phenomenon in fruit flies: traits could appear in response to environmental stress in an individual’s lifetime and then be passed down to future generations. Waddington proposed that this wasn’t the inheritance of acquired traits, but actually due to pre-existing genetic variation that had no effect until the flies were stressed. In the August issue of GENETICS, Fanti and Piacentini et al. revisit Waddington’s famous experiments with modern sequencing technology to show that this phenomenon can also be driven by newly arising DNA mutations.
The authors followed Waddington’s fairly simple experimental framework: take flies from natural populations and expose them to high temperatures for a short time during pupation. Observe the adult phenotypes, and then do it all again the next generation. Repeat this process until strange phenotypes emerge following the heat shock treatment.
The authors focused on four phenotypes caused by well-studied mutations in fruit flies, including sepia eye color and forked bristle mutations. These phenotypes began to appear after heat shock treatment between four and twelve generations after the experiment began. The scientists then selected for a phenotype by crossing the flies displaying it. They repeated this procedure until the phenotypes appeared not only after heat stress but were stably maintained in regular conditions.
They confirmed the presence of genetic mutations in the heat shocked mutant stocks using DNA sequencing. In the fixed mutant stocks, they found clear genetic causes of the mutant phenotypes. In two cases, a deletion mutation disrupted the protein coding sequence, and the other two genes carried transposable element insertions. None of the mutations were present in the genomes of the parental flies; these mutations were new, arising during the course of the experiment. Clearly, they were what allowed the phenotypes to be maintained stably without heat stress.
These results show that Waddington was wrong: inheritance of the abnormal post-heat shock phenotypes was not due to cryptic variation present in the parent lines. A different mechanism must be responsible. Heat shock stress may cause double-stranded DNA breaks, which can lead to deletions like the ones observed here. It may also activate transposable elements since the authors found higher levels of transposable element transcripts in flies that had been heat shocked.
But how could these new mutations appear in the same genes that were initially disabled by heat shock? How can a stress-dependent phenotype become genetically encoded? The authors suggest epigenetic changes may be involved. Heat stress could result in epigenetic alteration of particular loci to change their expression, leading to the observed heat-dependent phenotypes. This same epigenetic activity may make this stretch of DNA more susceptible to mutation, which could be very likely in the face of heat shock-induced double-stranded breaks or activated transposable elements.
If this model holds true, it could have serious evolutionary implications. In the wild, plastic traits like these post-heat shock phenotypes are often adaptive and help organisms survive in difficult, changing environments. It has been proposed that under natural selection such environmentally-induced traits can eventually become genetically encoded. Called the Baldwin Effect, this process illustrates how heritable behaviors like the human capacity for language might evolve. The results of this study provide a viable mechanism for this powerful evolutionary phenomenon.
CITATION
Canalization by Selection of de Novo Induced Mutations
Katie is a science writer at GSA. She did her PhD work on the evolutionary consequences of genetic conflict in fruit flies at the University of Georgia.
View all posts by Katie Pieper »Read more in
-
Where are they now? Rosalind Franklin Young Investigator Award recipients share updates on their research
Rosalind Franklin Young Investigator Award applications are open–make sure you submit your application or nomination of a colleague by September 30, 2024.
-
University of Minnesota researchers map genome of the last living wild horse species
The study, published in G3: Genes|Genomes|Genetics, is part of larger conservation efforts to save Przewalski’s horse.
-
Congratulations to the Spring 2024 DeLill Nasser Awardees!
GSA is pleased to announce the recipients of the DeLill Nasser Award for Professional Development in Genetics for Spring 2024! 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…
-
Carolyn Damilola: an NFS Rising Scientist on a lifelong quest to learn more
Carolyn Damilola is an NFS Rising Scientist from Nigeria doing respiratory system research and paving the way for scientists from underrepresented communities through mentorship.
-
What does a good microgrant proposal look like?
Members of the Microgrant Review Committee share their tips for a successful proposal.
-
The first piece of the facial recognition puzzle
New research in GENETICS gives a first peek at the molecular pathway involved in recognizing faces.
-
New Senior Editor Amy MacQueen joins GENETICS
A new senior editor is joining GENETICS in the Genome Integrity and Transmission section. We’re excited to welcome Amy MacQueen to the editorial team.
-
Block party on the zebrafish sex chromosome
Research in G3 identifies a gene regulatory block of the zebrafish genome responsible for overseeing the maternal-to-zygotic-transition.
-
Unraveling the mysteries of duckweed: epigenetic insights from Spirodela polyrhiza
Research published in G3 offers insight into the impact of DNA methylation on clonal propagation in asexually reproducing plants.
-
A microbiologist’s quest to understand CRISPR in bacterial self-defense
2024 Genetics Society of America Medal recipient Luciano Marraffini determined how CRISPR-Cas systems destroy genetic targets with precision, paving the way for gene editing technology development.
-
Unlocking mysteries of trait and disease heritability in dogs
2024 Edward Novitski Prize recipient Elaine Ostrander, a pioneer of the domestic dog model, discovered numerous genes affecting dog size, morphology, behavior, and disease susceptibility—many of which have relevance in humans.
-
GSA and collaborators Personal Genetics Education & Dialogue and Reclaiming STEM Institute launch NSF-funded BIO-LEAPS project to support culture change in genetics
We are thrilled to announce that the Genetics Society of America (GSA) is collaborating with the Personal Genetics Education & Dialogue (PGED) based in the Department of Genetics at Harvard Medical School, and the Reclaiming STEM Institute (RSI) on a Leading Culture Change Through Professional Societies of Biology (BIO-LEAPS) grant from the U.S. National Science…
-
Daman Saluja: Navigating Science and Policy in India
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 GSA Early Career Scientist…
-
A fly geneticist’s journey into discovering rules of organ development
2024 George W. Beadle Award recipient Deborah Andrew discovered new genes and pathways in Drosophila salivary gland organogenesis. Now, her work can help optimize cell secretion in therapeutic applications and fight malaria.
-
Małgorzata Gazda: How receiving the DeLill Nasser Award helped her land her dream job
Have you ever experienced an event that changes the course of your life, or in this case, your career? Małgorzata (Gosia) Gazda is Assistant Professor at the University of Montreal and in 2022, she received the DeLill Nasser Award for Professional Development in Genetics, which she used to attend and present at the 2022 Population,…
-
Hongyu Zhao joins GENETICS as new Senior Editor
A new senior editor is joining GENETICS in the Statistical Genetics and Genomics section. We’re excited to welcome Hongyu Zhao to the editorial team.
-
GSA Member Julio Molina Pineda Receives DeLill Nasser Award, Shines at TAGC 2024
“At any career stage, the GSA membership is an amazing investment for any genetics professional!” Julio Molina Pineda is a PhD Candidate in Cell and Molecular Biology and a Research Assistant at the University of Arkansas, and a Doctoral Academy Fellow at the Lewis Lab. In 2023, Julio was awarded the DeLill Nasser Award for…
-
In Memoriam: Ellsworth Herman Grell (1932–2023), a pioneer of Drosophila genome engineering and annotation
Ellsworth (Ed) Grell blessed the Drosophila community through three enduring legacies: as a pioneer of chromosome mechanics, as a primary organizer and synthesizer of genetic knowledge in Drosophila, and as a graceful mentor to those fortunate to have known him personally. Ed grew up in rural Nebraska, completed his undergraduate studies at Iowa State, and…
-
Congratulations to the #Fungal24 Poster Award winners!
We are pleased to announce the recipients of the GSA Poster Awards for posters presented at the 32nd Fungal Genetics Conference! Undergraduate and graduate student members of GSA were eligible for the awards, and a hard-working team of judges made the determinations. Congratulations to all! Felicia Ebot Ojong, The University of Georgia My research is focused…
-
Poster presentation tips for TAGC 2024
You’ve been selected to present a poster at The Allied Genetics Conference 2024 in March—you’ve celebrated, made plans to attend, now what? This is an exciting opportunity to showcase your research and engage with fellow members of the genetics community, so you want to make sure you’re prepared. We wanted to offer you some tips…
-
Maximize your TAGC 2024 experience
A guide to all that National Harbor & DC have to offer Are you joining us for The Allied Genetics Conference 2024 in March? Make the most of your #TAGC24 experience in National Harbor! We know the science will keep you busy, but you deserve to unwind and have some fun, so we’ve curated a…
-
Early Career Leadership Spotlight: Sarah Petrosky
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. Sarah PetroskyMultimedia SubcommitteeUniversity of Pittsburgh Research Interest I am interested in understanding adaptation that has been happening recently in populations by dissecting the ways that genes underlying an adaptation…
-
TAGC 2024 Early Career Award Winners
GSA is pleased to announce the winners of the early career awards presented at The Allied Genetics Conference 2024. These awards are specific to particular TAGC communities and recognize early career scientists’ outstanding work on their respective research organisms. The awardees will present their talks in keynote sessions at TAGC 2024. Don’t miss the opportunity…
-
Preeminent geneticists recognized with revamped GSA Awards
In 2022, GSA’s Board of Directors launched an audit to review the five major awards conferred by the Society. Today, we are thrilled to announce the recipients of the reimagined GSA Awards, including the new Genetics Society of America Early Career Medal. The scientists honored this year are recognized by their peers for their outstanding…
-
Fly Board funds outreach programs to spread the word about Drosophila research
In 2020, the Fly Board voted to use part of its reserve fund to support efforts to increase trainee participation as well as equity and diversity in the Drosophila community. An awards committee decides how the money will be spent each year, and from 2020–2022, the committee posted a very broad call for applications from…
-
New members of the GSA Board of Directors: 2024–2026
We are pleased to announce the election of four new leaders to the GSA Board of Directors: 2024 Vice President/2025 President Brenda Andrews Professor, University of Toronto It’s an honor to continue my association with the Society by serving as Vice President of the Board of Directors. I have broad knowledge of the ongoing activities…
-
The Fly Meeting is one-of-a-kind! Dros 2025 organizers share their excitement
The 66th Annual Drosophila Research Conference promises to be a meeting rich with the latest in Drosophila research as well as opportunities to advance your career and connect with a global community of 1,400+ scientists. The organizers Todd Nystul, Michelle Bland, Leila Rieder, Amanda Crocker, and Justin Crocker are hard at work, planning a conference…
-
Early Career Leadership Spotlight: Olufemi Osonowo
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. Olufemi Adekunle OsonowoCareer Development SubcommitteeDalhousie University Research Interest Metabolomics and genomics are two distinct but complimentary approaches that offer valuable insights into the underlying mechanisms of complex traits, such…
-
Early Career Leadership Spotlight: Hector Mendoza
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. Hector MendozaCommunication and Outreach SubcommitteeUniversity of Michigan Research Interest My research goals converge around the evolution of sexual reproduction. During my doctoral program, I investigated mitochondrial inheritance, a mechanism…