The study focuses on the evolution of “eusociality,” a system of collective living in which most members of a female-centric colony forego their reproductive rights and instead devote themselves to specialized tasks – such as hunting for food, defending the nest or caring for the young – that enhance the survival of the group. The study appears in the Proceedings of the National Academy of Sciences.
Eusociality is a rarity in the animal world, said Gene Robinson, a University of Illinois entomology professor and the director of the Institute for Genomic Biology, who led the study. Ants, termites, some bees and wasps, a few other arthropods and a couple of mole rat species are the only animals known to be eusocial.
Among bees, there are the “highly eusocial” honey bees and stingless bees, with a caste of sterile workers and a queen that functions primarily as a “giant, egg-laying machine,” Robinson said. And there are other, so-called “primitively eusocial” insects, usually involving a single mom who starts a nest from scratch and then, once she has raised enough workers, “kicks back and becomes a queen,” he said.
Illinois entomology professor Sydney Cameron, a collaborator on the study and a social insect evolution expert, dislikes the term “primitively eusocial” because it suggests that these bees are on their way to becoming more like stingless bees or honey bees. Eusociality is not a progressive evolution from the “primitive” to the “advanced” stage, she said.“They’re not striving to become highly eusocial,” Cameron said. “They don’t say to themselves, ‘If only I could become a honey bee!’ ”
“People talk about the evolution of eusociality,” Robinson said. “But we want to emphasize that these were independent evolutionary events. And we wanted to trace the independent stories of each.”
To accomplish this, the researchers worked with Roche Diagnostic Corp. to sequence active genes (those transcribed for translation into proteins) in nine species of bees representing every lifestyle from the solitary leaf-cutter bee, Megachile rotundata, to the highly eusocial dwarf honey bee, Apis florea. Then Illinois crop sciences professor and co-author Matt Hudson used the only available bee genome, that of the honey bee, Apis mellifera, as a guide to help assemble and identify the sequenced genes in the other species, and the team looked for patterns of genetic change that coincided with the evolution of the differing social systems.
“Are there genes that are unique to the primitively eusocial bees that aren’t found in the highly eusocial bees?” Cameron said. “Or if you lump all the eusocial bees together, are there unique genes that unite those groups compared to the solitaries?”
The analysis did find significant differences in gene sequence between the eusocial and solitary bees. The researchers also saw patterns of genetic change unique to either the highly eusocial or primitively eusocial bees. The frequency and pattern of these changes in gene sequence suggest “signatures of accelerated evolution” specific to each type of eusociality, and to eusociality in general, the researchers reported.“What we find is that there are some genes that show signatures of selection across the different independent evolutions (of eusocial bees),” Robinson said. “They might be representatives of the ‘gotta have it’ genes if you’re going to evolve eusociality. But others are more lineage-specific.”
This study was made possible with a one-gigabyte sequencing grant from 454 Life Sciences (Roche Diagnostics Corp.) by way of the Roche 1GB contest. The National Science Foundation and the National Institutes of Health also supported the research.
The study team also included researchers from Cornell University and from the Program in Ecology, Evolution and Conservation Biology and the Institute for Genomic Biology at Illinois.
Diana Yates | University of Illinois
Clock stars: Astrocytes keep time for brain, behavior
27.03.2017 | Washington University in St. Louis
Cryo-electron microscopy achieves unprecedented resolution using new computational methods
24.03.2017 | DOE/Lawrence Berkeley National Laboratory
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
27.03.2017 | Health and Medicine
27.03.2017 | Life Sciences
27.03.2017 | Earth Sciences