Genetic analysis of an island population of mice reveals that 19 quantitative trait loci are responsible for their impressive size.
Island populations of animals, isolated from their mainland relatives, have given us insight into evolution from the very birth of the field. In fact, studying finches on the Galápagos Islands helped Charles Darwin establish his theory of evolution.
Today, with the genetic tools available to us, studying island populations provides mechanistic clues into how these animals evolve traits that distinguish them from their mainland relatives. Gough Island, a small, remote island in the South Atlantic, is home to the largest wild house mice in the world. These mice, which were brought to the island on seal fishing and whaling ships about 200 years ago, are often double the weight of mainland mice. Two hundred years is a short span on the evolutionary timescale – meaning that this adaptive size change happened in as few as 400 generations!
A mouse from Gough Island (left) next to a mouse from the mainland.
The mice on Gough Island are the same subspecies as laboratory mice (Mus musculus domesticus), which allows researchers to use well-established genetic tools to investigate their evolution.
In their recent GENETICS paper, Gray et al. report that 19 quantitative trait loci (or QTL) are responsible for the size difference between island mice and mainland mice. QTL are regions of DNA that influence a quantitative trait – a characteristic that varies along a continuous scale, such as weight. While each of the discovered QTL has a modest effect on body size, the sum of these effects across loci explains much of the size difference between island and mainland mice. This mode of inheritance contrasts with monogenic traits, which are controlled by single genes, and with traits that are controlled by a few genes with large effects.
Gray et al. discovered that the biggest difference in growth rate between island and mainland mice occurred in the first six weeks of life, with the island mice’s accelerated growth leading to the overall size distinction between the two populations. The rapid evolution of the larger body size in the novel environment of the island suggests natural selection is the primary force at work. Gough Island mice have fewer predators and less competition, and the removal of those selective constraints may also contribute to their ability to grow larger.
CITATION Gray, M.M., Parmenter, M.D., Hogan, C.A., Ford, I., Cuthbert, R.J., Ryan, P.G., Broman, K.W., Payseur, B.A. 2015. Genetics of Rapid and Extreme Size Evolution in Island Mice. GENETICS, 201(1): 213-28. doi:10.1534/genetics.115.177790 http://www.genetics.org/content/201/1/213.full
Scientific Editor and Programs Manager. Genetics and Molecular Biology PhD. Find me on Twitter: @_sbay
View all posts by Sarah Bay »Read more in
-
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. Hongyu ZhaoSenior Editor Hongyu Zhao is the Ira V. Hiscock Professor of Biostatistics, Professor of Genetics, and Professor of Statistics and Data Science at Yale University. He received his BS in…
-
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…
-
Early Career Leadership Spotlight: Caroline Muirhead
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. Caroline MuirheadCommunication and Outreach SubcommitteeWorcester Polytechnic Institute Research Interest I didn’t always know I wanted to make science my career. In fact, I started college as an engineering major.…