These microscopic fellow travelers are collectively called the microbiome. Realization that every species of plant and animal is accompanied by a distinctive microbiome is old news.
But evidence of the impact that these microbes have on their hosts continues to grow rapidly in areas ranging from brain development to digestion to defense against infection to producing bodily odors.
Now, contrary to current scientific understanding, it also appears that our microbial companions play an important role in evolution. A new study, published online on July 18 by the journal Science, has provided direct evidence that these microbes can contribute to the origin of new species by reducing the viability of hybrids produced between males and females of different species.
“It was a high-risk proposition. The expectation in the field was that the origin of species is principally driven by genetic changes in the nucleus.
Our study demonstrates that both the nuclear genome and the microbiome must be considered in a unified framework of speciation,” said Associate Professor of Biological Sciences Seth Bordenstein who performed the study with post-doctoral fellow Robert Brucker.
They conducted their research using three species of the jewel wasp Nasonia. These tiny, match-head sized wasps parasitize blowflies and other pest flies, which make them useful for biological control.
“The wasps have a microbiome of 96 different groups of microorganisms,” said Brucker. Two of the species they used (N. giraulti and N. longicornis) only diverged about 400,000 years ago so they are closely related genetically. This closeness is also reflected in their microbiomes, which are quite similar. The third species (N. vitripennis), on the other hand, diverged about a million years ago so there are greater differences in both its genome and microbiome, he explained.
The mortality of hybrid offspring from the two closely related species was relatively low, about 8 percent, while the mortality rate of hybrid offspring between either of them and N. vitripennis was quite high, better than 90 percent, the researchers established.
“The microbiomes of viable hybrids looked extremely similar to those of their parents, but the microbiomes of those that did not survive looked chaotic and totally different,” Brucker reported.
The researchers showed that the incompatibilities that were killing the hybrids had a microbial basis by raising the wasps in a microbe-free environment. They were surprised to find that the germ-free hybrids survived just as well as purebred larvae. But when they gave the germ-free hybrids gut microbes from regular hybrids, their survival rate plummeted.
“Our results move the controversy of hologenomic evolution from an idea to an observed phenomenon,” said Bordenstein. “The question is no longer whether the hologenome exists, but how common it is?”
This research was supported by award DEB 1046149 from the National Science Foundation's Dimensions of Biodiversity program.
Further information can be found at the Bordenstein Lab, the author's blogs at Symbionticism and Live In Symbiosis, and the author's twitter feeds @Symbionticism and @LiveInSymbiosis.Visit Research News @ Vanderbilt for more research news from Vanderbilt. [Media Note: Vanderbilt has a 24/7 TV and radio studio with a dedicated fiber optic line and ISDN line. Use of the TV studio with Vanderbilt experts is free, except for reserving fiber time.]
-VU-Contact: David F. Salisbury, (615) 322-NEWS
David F. Salisbury | Vanderbilt University
Symbiotic bacteria: from hitchhiker to beetle bodyguard
28.04.2017 | Johannes Gutenberg-Universität Mainz
Nose2Brain – Better Therapy for Multiple Sclerosis
28.04.2017 | Fraunhofer-Institut für Grenzflächen- und Bioverfahrenstechnik IGB
More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.
Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...
Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.
"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...
The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.
Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...
The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...
Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.
Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...
28.04.2017 | Event News
20.04.2017 | Event News
18.04.2017 | Event News
28.04.2017 | Medical Engineering
28.04.2017 | Earth Sciences
28.04.2017 | Life Sciences