Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Color differences within and between species have common genetic origin

23.10.2009
Spend a little time people-watching at the beach and you're bound to notice differences in the amount, thickness and color of people's body hair. Then head to the zoo and compare people to chimps, our closest living relatives.

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:
Wittkopp: www.eeb.lsa.umich.edu/eeb/people/wittkopp/index.html
Science: -http://www.sciencemag.org/

Nancy Ross-Flanigan | EurekAlert!
Further information:
http://www.umich.edu

More articles from Life Sciences:

nachricht Individual Receptors Caught at Work
19.10.2017 | Julius-Maximilians-Universität Würzburg

nachricht Rapid environmental change makes species more vulnerable to extinction
19.10.2017 | Universität Zürich

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

Electrode materials from the microwave oven

19.10.2017 | Materials Sciences

New material for digital memories of the future

19.10.2017 | Materials Sciences

Physics boosts artificial intelligence methods

19.10.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>