Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Study shows how plants sort and eliminate genes over millennia

10.03.2011
Hybrid plants with multiple genome copies show evidence of preferential treatment of the genes from one ancient parent over the genes of the other parent, even to the point where some of the unfavored genes eventually are deleted.

Brian Dilkes, an assistant professor of genetics at Purdue University, worked with a team of scientists at the University of California Davis and University of Southern California to study the genome of Arabidopsis suecica, a hybrid species with four chromosome sets formed tens of thousands of years ago from a cross between Arabidopsis arenosa and Arabidopsis thaliana, a plant commonly used in laboratories for genetic research. Dilkes said the findings, published in the journal Genome Biology and featured as an editor's choice article in the journal Science, give a glimpse into the evolutionary forces and ultimate fates of genes contributed by the two parents to a hybrid

"There often is no visible signature of these genes when we look at the plants with a microscope, but we can still observe those genes in the genome sequence," Dilkes said. "Moreover, the ability to make crosses between Arabidopsis thaliana and Arabidopsis arenosa gives us the opportunity to compare laboratory-derived plants that were generated yesterday with naturally occurring species from the wild and compare the two kinds of species hybrids. This is essentially allowing us an opportunity to 'replay the evolutionary tape,' in the words of Stephen J. Gould."

The researchers compared the genomes and gene expression among Arabidopsis suecica plants that have evolved over tens of thousands of years to similar species of hybrids made in the lab from fresh crosses.

When the contribution of genes from each parent was compared, they were not equal. One parent's genes were preferentially expressed at higher levels. In the cases where that happened, it was three times more likely that the preferentially expressed genes came from Arabidopsis arenosa.

The team also found that gene pairs that are co-expressed in similar tissues are preferentially expressed from the same parent. Even in the rare cases when an Arabidopsis thaliana gene was more abundantly expressed in the hybrid, co-expressed genes would also be preferentially expressed from the Arabidopsis thaliana copy.

"Our findings suggest an additional network dependence, where genes fine-tuned to work together within either parental species prior to hybridization are more likely to be expressed together in the hybrid. This, in turn, ensures that these genes acquired from one parental species are kept together and are not lost in the genome over time," said Peter Chang, a graduate student at USC and lead author on the paper. "Plants have had a remarkable ability to adapt to different conditions throughout Earth's history, and we are just beginning to understand some of ways this is done."

Previous work has shown that plant genomes with historical duplications from tens of millions of years ago have lost one of the two copies in large blocks along the chromosome, consistent with the preferential loss of one parent's contribution.

Dilkes said the retained genes may have a role in the plants' fitness but genes that weren't expressed would be deleted from the genome.

"The genome is moving toward a two-copy organization, a diploid, by preferentially deleting one parent. When others have looked at genomes that have ancient duplications they see large blocks of duplications in which one block has a large number of genes and the other has a sparse gene content," Dilkes said. "Perhaps a cause of this pattern in the organization of genomes is preferential expression, and, all other things being equal, the gene that is more abundantly expressed will carry a greater proportion of the fitness load for any essential function."

The National Science Foundation funded the research.

Writer: Brian Wallheimer, 765-496-2050, bwallhei@purdue.edu

Sources: Brian Dilkes, 765-494-2584, bdilkes@purdue.edu

Peter Chang, 213-821-4000, Peter.Chang@usc.edu

Ag Communications: (765) 494-2722;
Keith Robinson, robins89@purdue.edu
Agriculture News Page

Brian Wallheimer | EurekAlert!
Further information:
http://www.purdue.edu

More articles from Life Sciences:

nachricht A Map of the Cell’s Power Station
18.08.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau

nachricht On the way to developing a new active ingredient against chronic infections
18.08.2017 | Deutsches Zentrum für Infektionsforschung

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

A Map of the Cell’s Power Station

18.08.2017 | Life Sciences

Engineering team images tiny quasicrystals as they form

18.08.2017 | Physics and Astronomy

Researchers printed graphene-like materials with inkjet

18.08.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>