Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Sunflower speciation highlights roles for transposable elements in evolution

24.10.2006
In a finding that furthers our understanding of how hybridization may contribute to genome changes and the evolution of new species, researchers have found that the genomes of three sunflower species that arose in evolution as hybrids of the same two parental types have undergone a massive proliferation of genetic entities known as transposable elements.

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.

Heidi Hardman | EurekAlert!
Further information:
http://www.cell.com
http://www.current-biology.com

Further reports about: Transposable hybridization proliferation species sunflower

More articles from Life Sciences:

nachricht Single-stranded DNA and RNA origami go live
15.12.2017 | Wyss Institute for Biologically Inspired Engineering at Harvard

nachricht New antbird species discovered in Peru by LSU ornithologists
15.12.2017 | Louisiana State 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: First-of-its-kind chemical oscillator offers new level of molecular control

DNA molecules that follow specific instructions could offer more precise molecular control of synthetic chemical systems, a discovery that opens the door for engineers to create molecular machines with new and complex behaviors.

Researchers have created chemical amplifiers and a chemical oscillator using a systematic method that has the potential to embed sophisticated circuit...

Im Focus: Long-lived storage of a photonic qubit for worldwide teleportation

MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.

Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...

Im Focus: Electromagnetic water cloak eliminates drag and wake

Detailed calculations show water cloaks are feasible with today's technology

Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...

Im Focus: Scientists channel graphene to understand filtration and ion transport into cells

Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.

To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...

Im Focus: Towards data storage at the single molecule level

The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.

Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

 
Latest News

Engineers program tiny robots to move, think like insects

15.12.2017 | Power and Electrical Engineering

One in 5 materials chemistry papers may be wrong, study suggests

15.12.2017 | Materials Sciences

New antbird species discovered in Peru by LSU ornithologists

15.12.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>