Featured Research

from universities, journals, and other organizations

Out of Africa: How the fruit fly made its way in the world

Date:
May 22, 2011
Source:
Veterinärmedizinische Universität Wien
Summary:
The fruit fly Drosophila melanogaster used to be found only in sub-Saharan Africa, but about 10,000 years ago it began to colonize Asia and Europe. This period saw the start of human agriculture and the domestication of cats and oxen, but we have no evidence to suggest that early agricultural practices were associated with significant global warming. So, the fly's northerly spread is thought to relate to genetic factors rather than to environmental changes. Now researchers in Austria offer an intriguing clue to the mechanism.

Fruit flies in breeding containers.
Credit: Vetmed Uni Vienna / Wassermann

The fruit fly Drosophila melanogaster used to be found only in sub-Saharan Africa, but about 10,000 years ago it began to colonize Asia and Europe. This period saw the start of human agriculture and the domestication of cats and oxen, but we have no evidence to suggest that early agricultural practices were associated with significant global warming. So, the fly's northerly spread is thought to relate to genetic factors rather than to environmental changes.

An intriguing clue to the mechanism is now provided by Christian Schlötterer from the Institute of Population Genetics at the University of Veterinary Medicine, Vienna. His results are published in the journal PLoS Genetics.

Fruit flies that moved from sub-Saharan Africa found themselves confronted by conditions very different from those to which they were accustomed. Most obviously, the average temperatures were considerably lower and so it is no surprise that the flies had to adapt to cope with life in the north. As a result of thousands of years of evolution, populations in sub-Saharan African and in Europe now differ dramatically in a number of characteristics known to relate to temperature (such as pigmentation, size and resistance to cold). Schlötterer's previous work had suggested that a single gene, interestingly known as cramped (crm), might be involved in helping the flies survive in a colder environment but conclusive proof was lacking.

The crm protein is a transcription factor, so Jean-Michel Gibert in Schlötterer's laboratory decided to investigate what genes it could regulate, continuing to work on the project following his move to the University of Geneva. Gibert and Schlötterer focused in particular on genes known to be involved in wing development, such as the so-called cubitus interruptus (ci) gene, the regulation of which is known to depend on temperature. Satisfyingly, they were able to show that crm is absolutely required for the inactivation of the ci gene.

The scientists reasoned that if the crm protein is important in the response to temperature it should be possible to show that the variants -- or alleles -- of the crm gene found in Europe function differently from the alleles found in flies in sub-Saharan Africa. To "amplify" any differences in properties, they employed a sophisticated genetic trick, removing the effects of other sites in the fly's genome. In the presence of different crm alleles they examined the effects of temperature changes on the expression of the ci gene as well as on such characteristics as abdominal pigmentation in females and sex combs in males, traits known to be influenced by temperature. The results were striking: different crm alleles were associated with significant differences in the effects of temperature on these characteristics.

crm was found to limit distinct processes at different temperatures, strongly suggesting that changes in crm could have been involved in buffering the effects of different temperatures on the fly. The results represent an exciting new direction in the understanding of evolution. As Schlötterer says, "We normally imagine evolution proceeding by the acquisition of new functions. But the fly's adaptation to a colder environment seems instead to have been accompanied by changes to a master regulator to ensure that previously existing functions were retained despite the changed circumstances."


Story Source:

The above story is based on materials provided by Veterinärmedizinische Universität Wien. Note: Materials may be edited for content and length.


Journal Reference:

  1. Jean-Michel Gibert, François Karch, Christian Schlötterer. Segregating Variation in the Polycomb Group Gene cramped Alters the Effect of Temperature on Multiple Traits. PLoS Genetics, 2011; 7 (1): e1001280 DOI: 10.1371/journal.pgen.1001280

Cite This Page:

Veterinärmedizinische Universität Wien. "Out of Africa: How the fruit fly made its way in the world." ScienceDaily. ScienceDaily, 22 May 2011. <www.sciencedaily.com/releases/2011/04/110427070859.htm>.
Veterinärmedizinische Universität Wien. (2011, May 22). Out of Africa: How the fruit fly made its way in the world. ScienceDaily. Retrieved September 1, 2014 from www.sciencedaily.com/releases/2011/04/110427070859.htm
Veterinärmedizinische Universität Wien. "Out of Africa: How the fruit fly made its way in the world." ScienceDaily. www.sciencedaily.com/releases/2011/04/110427070859.htm (accessed September 1, 2014).

Share This




More Plants & Animals News

Monday, September 1, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

We've Got Mites Living In Our Faces And So Do You

We've Got Mites Living In Our Faces And So Do You

Newsy (Aug. 30, 2014) — A new study suggests 100 percent of adult humans (those over 18 years of age) have Demodex mites living in their faces. Video provided by Newsy
Powered by NewsLook.com
Washington Wildlife Center Goes Nuts Over Baby Squirrels

Washington Wildlife Center Goes Nuts Over Baby Squirrels

Reuters - US Online Video (Aug. 30, 2014) — An animal rescue in Washington state receives an influx of orphaned squirrels, keeping workers busy as they nurse them back to health. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
Experimental Ebola Drug ZMapp Cures Lab Monkeys Of Disease

Experimental Ebola Drug ZMapp Cures Lab Monkeys Of Disease

Newsy (Aug. 29, 2014) — In a new study, a promising experimental treatment for Ebola managed to cure a group of infected macaque monkeys. Video provided by Newsy
Powered by NewsLook.com
Killer Amoeba Found in Louisiana Water System

Killer Amoeba Found in Louisiana Water System

AP (Aug. 28, 2014) — State health officials say testing has confirmed the presence of a killer amoeba in a water system serving three St. John the Baptist Parish towns. (Aug. 28) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins