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 What happens in the cell nucleus after fertilization
06.12.2016 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt

nachricht Researchers uncover protein-based “cancer signature”
05.12.2016 | Universität Basel

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Simple processing technique could cut cost of organic PV and wearable electronics

06.12.2016 | Materials Sciences

3-D printed kidney phantoms aid nuclear medicine dosing calibration

06.12.2016 | Medical Engineering

Robot on demand: Mobile machining of aircraft components with high precision

06.12.2016 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>