Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Geneticists discover genes that make fruit fly hybrids sterile

While hybrids -- the result of the mating of two different species -- may offer interesting and beneficial traits, they are usually sterile or unable to survive. For example, a mule, the result of the mating of a horse and a donkey, is sterile.

Now, Cornell researchers have made the first identification of a pair of genes in any species that are responsible for problems unique to hybrids. Specifically, the researchers have found two genes from two fruit fly species (Drosophila melanogaster and D. simulans) that interfere with each other, thereby preventing the production of male offspring.

The finding may eventually shed light on what causes lethality or sterility in hybrids in general and, in a larger sense, offers clues to how species evolve from common ancestors.

The research, published in the Nov. 24 issue of Science, focuses on a rarely occurring mutation in a D. melanogaster gene called "Hmr" (Hybrid male rescue) and a similar mutation in a D. simulans gene called "Lhr" (Lethal hybrid rescue) that make these genes nonfunctional. When either of these genes is "turned off" and then crossed with the other fruit fly species, the males survive.

... more about:
»Lhr »evolved »melanogaster »species

"We have found the first example of two genes that interact to cause lethality in a species hybrid," said the paper's senior author, Daniel Barbash, assistant professor in Cornell's Department of Molecular Biology and Genetics.

The finding supports the Dobzhansky-Muller model, a theory from the 1930s that suggests hybrid incompatibilities (such as death or sterility) are caused by genes that have evolved from a common ancestor but diverged in each of the species. More specifically, in the common ancestor, these genes may have worked perfectly well together. But, as each gene evolved in its own species, it began to code for proteins that no longer work in the other species.

In this case, when genes from each fruit fly species were compared with each other, the researchers found the Hmr gene in D. melanogaster and the Lhr gene in D. simulans each evolved much faster than most other genes and diverged due to natural selection, a genetic change due to a pressure that benefits the survival of a species. The researchers would like to learn what these genes normally do within their species in order to understand why they are evolving so fast.

The Dobzhansky-Muller model also proposes that these evolved genes depend on each other to cause hybrid incompatibilities.

However, when Barbash and his colleagues cloned each gene and inserted an Lhr gene from D. simulans into D. melanogaster, the two genes did not interfere with each other in the engineered D. melanogaster strain even though the Lhr and Hmr genes interfere with each other in hybrids.

"This tells us there must be other things involved in the hybrid" that impacts the incompatible pairing of these genes, said Barbash. In future work the researchers hope to determine whether the hybrids die because of additional genes like Hmr and Lhr, or because of more subtle differences between the chromosomes of these two species.

The study was funded by the National Institutes of Health.

| EurekAlert!
Further information:

Further reports about: Lhr evolved melanogaster species

More articles from Life Sciences:

nachricht Biologists unravel another mystery of what makes DNA go 'loopy'
16.03.2018 | Emory Health Sciences

nachricht Scientists map the portal to the cell's nucleus
16.03.2018 | Rockefeller University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Locomotion control with photopigments

Researchers from Göttingen University discover additional function of opsins

Animal photoreceptors capture light with photopigments. Researchers from the University of Göttingen have now discovered that these photopigments fulfill an...

Im Focus: Surveying the Arctic: Tracking down carbon particles

Researchers embark on aerial campaign over Northeast Greenland

On 15 March, the AWI research aeroplane Polar 5 will depart for Greenland. Concentrating on the furthest northeast region of the island, an international team...

Im Focus: Unique Insights into the Antarctic Ice Shelf System

Data collected on ocean-ice interactions in the little-researched regions of the far south

The world’s second-largest ice shelf was the destination for a Polarstern expedition that ended in Punta Arenas, Chile on 14th March 2018. Oceanographers from...

Im Focus: ILA 2018: Laser alternative to hexavalent chromium coating

At the 2018 ILA Berlin Air Show from April 25–29, the Fraunhofer Institute for Laser Technology ILT is showcasing extreme high-speed Laser Material Deposition (EHLA): A video documents how for metal components that are highly loaded, EHLA has already proved itself as an alternative to hard chrome plating, which is now allowed only under special conditions.

When the EU restricted the use of hexavalent chromium compounds to special applications requiring authorization, the move prompted a rethink in the surface...

Im Focus: Radar for navigation support from autonomous flying drones

At the ILA Berlin, hall 4, booth 202, Fraunhofer FHR will present two radar sensors for navigation support of drones. The sensors are valuable components in the implementation of autonomous flying drones: they function as obstacle detectors to prevent collisions. Radar sensors also operate reliably in restricted visibility, e.g. in foggy or dusty conditions. Due to their ability to measure distances with high precision, the radar sensors can also be used as altimeters when other sources of information such as barometers or GPS are not available or cannot operate optimally.

Drones play an increasingly important role in the area of logistics and services. Well-known logistic companies place great hope in these compact, aerial...

All Focus news of the innovation-report >>>



Industry & Economy
Event News

Ultrafast Wireless and Chip Design at the DATE Conference in Dresden

16.03.2018 | Event News

International Tinnitus Conference of the Tinnitus Research Initiative in Regensburg

13.03.2018 | Event News

International Virtual Reality Conference “IEEE VR 2018” comes to Reutlingen, Germany

08.03.2018 | Event News

Latest News

Wandering greenhouse gas

16.03.2018 | Earth Sciences

'Frequency combs' ID chemicals within the mid-infrared spectral region

16.03.2018 | Physics and Astronomy

Biologists unravel another mystery of what makes DNA go 'loopy'

16.03.2018 | Life Sciences

Science & Research
Overview of more VideoLinks >>>