Featured Research

from universities, journals, and other organizations

Genome of rare fruit fly, Drosophila mauritiana, sequenced: New method measures genetic variability of populations

Date:
December 17, 2012
Source:
University of Veterinary Medicine -- Vienna
Summary:
In the twentieth century the sequencing of an entire genome of a higher (eukaryotic) organism was a truly exceptional event -- by the end of the year 2000, only four such sequences were available. Since then, technological advances have put whole-genome sequencing within the reach of many more groups and new sequences have appeared at regular intervals. Now the genome of the fruit fly Drosophila mauritiana, a close relative of the well-known (and previously sequenced) Drosophila melanogaster has been sequenced.

In the twentieth century the sequencing of an entire genome of a higher (eukaryotic) organism was a truly exceptional event -- by the end of the year 2000, only four such sequences were available. Since then, technological advances have put whole-genome sequencing within the reach of many more groups and new sequences have appeared at regular intervals. Viola Nolte in the group of Christian Schlötterer at the University of Veterinary Medicine, Vienna has just published the first whole-genome sequence of a eukaryote to be determined at this university.

The results are published in the current issue of the journal Genome Research and reveal intriguing details about the evolution of the species.

The species in question is the fruit fly Drosophila mauritiana, a close relative of the well known (and previously sequenced) Drosophila melanogaster that swarms around our fruit bowls in summer. Nolte and colleagues now present a complete genomic sequence, annotating it to indicate the various genes it contains. The information will naturally be extremely useful to all those who are working on this organism.

But the present study goes much, much further. Schlötterer's group has recently developed powerful analytic methods for measuring the genetic variability of populations. In contrast to its widespread cousin, Drosophila mauritiana is only found on the island of Mauritius and it might be expected that the species' highly restricted distribution would lead to a relatively low rate of variability. Surprisingly, however, Nolte and her colleagues found that its genome is highly diverse, with polymorphisms (genetic variation) present across the chromosomes. Interestingly, the polymorphisms are not evenly distributed throughout the genome. Instead, the researchers observed that within the highly variable regions there are two large areas where the sequence is much more highly conserved. Such "troughs in variability" are thought to be the result of selective sweeps: newly arising mutations confer so great a selective advantage on the flies in question that they spread rapidly through the population until they become "fixed," or present in essentially all individuals.

One of the classical tenets of genetics is that when a parent carries two different versions of a gene at a particular locus, each of the so-called alleles has an equal probability of being passed to the next generation. Recently, however, it has become clear that certain genes are able to "cheat" and ensure that they are preferentially transmitted to the offspring. The simplest model involves two genes close together, of which one encodes a poison to which the other confers resistance. The poison kills all the gametes that do not contain the resistance gene, effectively ensuring the rapid spread of the allele in question through the genome. Might the two "troughs in variability" in the Drosophila mauritiana genome have arisen from an intragenomic conflict of this kind? It is hard to answer this question with certainty. However, one of the two troughs that Nolte identified contains the so-called Odysseus gene, which has previously been suggested to be involved in genomic conflict in the closely related Drosophila simulans. The other might relate to a second system characterized in Drosophila simulans.

The fact that two areas of the Drosophila mauritiana genome vary considerably less than surrounding regions suggests that some of the genes present have recently been involved in intragenomic conflicts. And these may indirectly help ensure the species' identity. As Schlötterer explains, "the biggest challenge for a newly separated species is to avoid being subsumed back into the species from which it derived. The weapons used in intragenomic conflicts also work against hybrids with related species so we can speculate that they act as a type of 'speciation gene'. It will be intriguing to study whether this has been the case for the Mauritius fruit flies."


Story Source:

The above story is based on materials provided by University of Veterinary Medicine -- Vienna. Note: Materials may be edited for content and length.


Journal Reference:

  1. V. Nolte, R. V. Pandey, R. Kofler, C. Schlotterer. Genome-wide patterns of natural variation reveal strong selective sweeps and ongoing genomic conflict in Drosophila mauritiana. Genome Research, 2012; DOI: 10.1101/gr.139873.112

Cite This Page:

University of Veterinary Medicine -- Vienna. "Genome of rare fruit fly, Drosophila mauritiana, sequenced: New method measures genetic variability of populations." ScienceDaily. ScienceDaily, 17 December 2012. <www.sciencedaily.com/releases/2012/12/121217102651.htm>.
University of Veterinary Medicine -- Vienna. (2012, December 17). Genome of rare fruit fly, Drosophila mauritiana, sequenced: New method measures genetic variability of populations. ScienceDaily. Retrieved September 18, 2014 from www.sciencedaily.com/releases/2012/12/121217102651.htm
University of Veterinary Medicine -- Vienna. "Genome of rare fruit fly, Drosophila mauritiana, sequenced: New method measures genetic variability of populations." ScienceDaily. www.sciencedaily.com/releases/2012/12/121217102651.htm (accessed September 18, 2014).

Share This



More Plants & Animals News

Thursday, September 18, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: Elephant Undergoes Surgery in Tbilisi Zoo

Raw: Elephant Undergoes Surgery in Tbilisi Zoo

AP (Sep. 18, 2014) — Grand the elephant has successfully undergone surgery to remove a portion of infected tusk at Tbilisi Zoo in Georgia. British veterinary surgeons used an electric drill to extract the infected piece. (Sept. 18) Video provided by AP
Powered by NewsLook.com
Chimp Violence Study Renews Debate On Why They Kill

Chimp Violence Study Renews Debate On Why They Kill

Newsy (Sep. 17, 2014) — The study weighs in on a debate over whether chimps are naturally violent or become that way due to human interference in the environment. Video provided by Newsy
Powered by NewsLook.com
Some Tobacco Farmers Thrive Amid Challenges

Some Tobacco Farmers Thrive Amid Challenges

AP (Sep. 16, 2014) — The South's tobacco country is surviving, and even thriving in some cases, as demand overseas keeps growers in the fields of one of America's oldest cash crops. (Sept. 16) Video provided by AP
Powered by NewsLook.com
Scientists Given Rare Glimpse of 350-Kilo Colossal Squid

Scientists Given Rare Glimpse of 350-Kilo Colossal Squid

AFP (Sep. 16, 2014) — Scientists say a female colossal squid weighing an estimated 350 kilograms (770 lbs) and thought to be only the second intact specimen ever found was carrying eggs when discovered in the Antarctic. Duration: 00:47 Video provided by AFP
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