The fly is one of a dozen species of Drosophila to have recently had their genomes sequenced, information that should provide abundant opportunities for identifying genetic changes that cause females of this species, and not others, to retain their fertilized eggs until they are ready to hatch.
The result was so surprising that the scientists initially thought it was a mistake.
“The student who was timing things came a said ‘wow, these eggs in this species really develop quickly’ sometimes in less than an hour. That’s not possible,” said Therese Markow, a professor of biology who led the project. “When I went and actually looked at them I saw that they were depositing something that was very advanced, that hatched into a larva right away. In several cases they were hatching as they were being laid.”
Even those Seychelles fly eggs that emerged unhatched were at an advanced state of development, the team reports in forthcoming issue of the Journal of Evolutionary Biology. Most larvae emerged within two hours compared to an average of nearly 23 hours for the other 10 species in the study.
The Seychelles flies also laid larger eggs--nearly double the average volumes found for the other species--and their ovaries have fewer threadlike structures called ovarioles in which insect eggs mature before fertilization.
Live birth could result from changes to the male reproductive strategy as well. Proteins found in the semen of the well-known lab fruit fly, Drosophila melanogaster, stimulate egg laying in the female. A modification of these signals could be responsible for the switch.
“That signaling mechanism between the male and the female has changed. We don’t know the basis for it, but we ought to be looking,” Markow said. “It’s very interesting. It tells you who’s really going to be able control reproduction.”
Early hatching offers advantages, the authors say. Mobile larvae can burrow into the ground to avoid becoming inadvertent hosts to the eggs of parasitic insects or a predator’s meal. But harboring offspring for a longer period of time costs the female.
The opportunity to take that risk may come with specialization. The Seychelles flies feed only on the fruit of the morinda tree, a tropical plant that produces year round, but is toxic to other fruit flies, giving this single species exclusive access.
One other fly in the study, Drosophila yakuba, also occasionally laid larvae instead of eggs, and their eggs also hatched fairly quickly, most in under 14 hours. It too specializes in a particular fruit, that of the Pandanus tree.
The Seychelles flies, Drosophila sechellia and D. yakuba are two of about 250 species held by the Drosophila Species Stock Center, which moved to UC San Diego this fall.
Contact: Therese Markow (email@example.com)
Susan Brown | Newswise Science News
Researchers identify how bacterium survives in oxygen-poor environments
22.11.2017 | Columbia University
Researchers discover specific tumor environment that triggers cells to metastasize
22.11.2017 | University of California - San Diego
The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.
Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....
The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.
Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...
Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.
That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...
Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.
During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....
The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.
Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...
15.11.2017 | Event News
15.11.2017 | Event News
30.10.2017 | Event News
22.11.2017 | Medical Engineering
22.11.2017 | Materials Sciences
22.11.2017 | Health and Medicine