The body hair difference is even more pronounced between the two species than within our own species.
Do the same genes cause both types of variation? Biologists have puzzled over that question for some time, not just with respect to people, chimps and body hair, but for all sorts of traits that differ within and between species. Now, a study by University of Michigan researchers shows that, at least for body color in fruit flies, the two kinds of variation have a common genetic basis. The research, led by evolutionary biologist Patricia Wittkopp, appears in the Oct. 23 issue of the journal Science.
Wittkopp's group explored the genetic underpinnings of pigmentation differences within and between a pair of closely related fruit fly species: Drosophila americana, which is dark brown, and Drosophila novamexicana, which is light yellow.
"We started by asking which parts of the genome contribute to the pigmentation difference between species," said Wittkopp, an assistant professor of ecology and evolutionary biology. Genetic mapping narrowed the search to two regions that happened to contain genes already known to affect pigmentation. The researchers then focused on one particular gene, known as tan, and used fine-scale genetic mapping to determine that evolutionary changes in that specific gene, not another gene in the same region, have contributed to the pigmentation difference.
To confirm that finding, the team transferred copies of the tan gene from the yellow species into flies of a completely different species, Drosophila melanogaster, and then did the same thing with copies of the tan gene from the brown species. The only difference between the two groups of altered flies was the transferred gene, "and that difference was enough to result in pigmentation differences," Wittkopp said.
Confident that the tan gene was responsible for part of the color difference between species, Wittkopp and coworkers investigated color variation within the brown species. Some flies in that species are noticeably darker than others, and previous experiments have suggested that the basis for the difference is genetic, rather than environmental.
Again using genetic mapping, the researchers found evidence that the tan gene also contributes to color variation among individuals within the brown species. Going a step further, they showed that it is not just the same gene that contributes to color differences within and between species, but also the same genetic changes within this gene. Currently, the team is trying to pinpoint the exact genetic change (or changes) within the tan gene that is responsible for the color shift.
Although this study focused on fruit flies, the work could lead to better understanding of patterns of variation throughout nature, Wittkopp said. "We're using a model system, but when you get down to the basic mechanisms of inheritance---how information is passed from one generation to the next---the process is essentially the same in all living things. While we can't extrapolate about the specific genes involved, it is fair to say that mutations contributing to both variation within species and divergence between species may be a common source of evolutionary change."
Wittkopp's coauthors on the Science paper were undergraduate students Emma Stewart, Laura Shefner, Gabriel Smith-Winberry, Saleh Akhras and Elizabeth Thompson; graduate student Lisa Arnold; and technicians Adam Neidert and Belinda Haerum.
The researchers received funding from the National Science Foundation, the Margaret and Herman Sokol Endowment for Faculty and Graduate Student Research and the University of Michigan.For more information:
Nancy Ross-Flanigan | EurekAlert!
Novel mechanisms of action discovered for the skin cancer medication Imiquimod
21.10.2016 | Technische Universität München
Second research flight into zero gravity
21.10.2016 | Universität Zürich
Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.
"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...
In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.
A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...
By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.
"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...
COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.
In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...
'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.
Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...
14.10.2016 | Event News
14.10.2016 | Event News
12.10.2016 | Event News
21.10.2016 | Health and Medicine
21.10.2016 | Information Technology
21.10.2016 | Materials Sciences