The findings are reported by Mark Ungerer and colleagues at Kansas State University and appear in the October 24th issue of the journal Current Biology, published by Cell Press.
Theory predicts that for diploid species--that is, those possessing two sets of chromosomes, like most animals and plants--the origin of new species through inter-species hybridization may be facilitated by rapid reorganization of genomes. Previous work on three independently derived hybrid sunflower species has validated this mode of speciation by documenting novel structural rearrangements in their chromosomes, as well as large-scale increases in nuclear DNA content. The nuclear-genome size differences between the hybrids and their parental taxa occur in spite of the fact that all species possess the same number of chromosomes and are diploids.
In the new work, the researchers have determined that the genome size differences between the hybrid and parental sunflower species are associated with a massive proliferation of transposable genetic elements that has occurred independently in the genome of each hybrid species. Transposable elements, made famous by Barbara McClintock in her study of their behavior in maize, are related to infectious retroviruses and are capable of multiplying and inserting themselves at different points throughout a host genome. They are found in virtually all eukaryotic genomes.
The new findings not only add an interesting twist to the origin of new sunflower species through hybridization, but also suggest that the sunflower system may emerge as an excellent model group for studying the natural forces influencing the activation and proliferation of transposable elements in plants. This is because in addition to their hybrid origins, each of the three hybrid species is adapted to, and evolved in, a so-called abiotically extreme environment--two of the species are found in desert environments, while the third is adapted to salt marshes. Both hybridization and abiotic stress have been implicated as natural agents of activation and proliferation of transposable elements.
For a chimpanzee, one good turn deserves another
27.06.2017 | Max-Planck-Institut für Mathematik in den Naturwissenschaften (MPIMIS)
New method to rapidly map the 'social networks' of proteins
27.06.2017 | Salk Institute
An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.
Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...
Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.
Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...
Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.
As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...
Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.
With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...
Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine
Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...
19.06.2017 | Event News
13.06.2017 | Event News
13.06.2017 | Event News
28.06.2017 | Awards Funding
28.06.2017 | Earth Sciences
28.06.2017 | Physics and Astronomy