(Press-News.org) Complex heritable traits are not only determined by changes in the DNA sequence. Scientists from the University of Groningen Bioinformatics Centre, together with their French colleagues, have shown that epigenetic marks can affect traits such as flowering time and architecture in plants. Furthermore, these marks are passed on for many generations in a stable manner. Their results were published in Science Express on Thursday, 6 February 2014. It seems that a revision of Genetics textbooks is now in order.
We've all been taught that DNA is the physical foundation of heredity. Our genes are spelled out in the four famous letters A, T, C and G, which together form the genetic code. A single letter change in this code can lead to a gene ceasing to function or failing to work properly.
The fact that the functioning of our genes is also affected by epigenetic marks has been known for decades. For example, the nucleotide cytosine (the C in the genetic code) can be changed into a methylcytosine. This cytosine methylation, which is one type of epigenetic mark, is typically associated with repression of gene activity.
Epigenetic inheritance
'While in mammals epigenetic marks are typically reset every generation, in plants no such dramatic resetting takes place. This opens the door to epigenetic inheritance in plants: epigenetic changes that are acquired in one generation tend to be stably passed on to the next generation', explains Frank Johannes, assistant professor at the GBIC and co-lead scientist for the Science Express study.
Johannes's French colleagues have produced inbred strains of the model plant Arabidopsis, in which the epigenetic marks vary between strains although the DNA sequence is almost identical. Nevertheless, these strains show marked differences in appearance, which are passed on to later generations.
Complex traits
In the new study, Johannes and his French colleagues have successfully linked variation in epigenetic markers to complex traits such as flowering time and plant architecture in these Arabidopsis strains. They employed techniques that are typically used by geneticists to locate the DNA regions with sequence variations that contribute to complex traits. These are called quantitative trait loci or QTLs.
Breakthrough
Johannes: 'We used the same method to locate regions in the DNA, not with different sequences but with different epigenetic marks that contribute to certain traits in the plant.' It is the first time that epigenetic differences have been unequivocally shown to contribute to heritable traits. 'This is a breakthrough, because it changes the way we view genetics. And it may even be of huge economic importance.'
Commercially interesting
Although the Science Express paper is based on heritability over just seven generations, other results with the Arabidopsis strains show that epigenetic traits are stably inherited for at least 20 generations. Johannes: 'Such stable traits can be of interest to plant breeders. Apart from variations in the gene sequence, epigenetic variation may contribute to commercially interesting traits.'
Evolution
The epigenetic markers may also affect evolution, independent of DNA sequence. 'They cause variation on which natural selection can act', Johannes explains. As such, traits caused by epigenetic variation may make an independent contribution to changes in a species. 'Our findings were made using inbred strains, but we also have evidence that we can find some of the same epigenetic QTLs in wild populations of this species as well.' This suggests it is not just a laboratory artefact but something that plays a role in nature.
Revision textbooks
Johannes points out that 'because epigenetic inheritance differs between plants and mammals, it is by no means certain that similar processes play a role in mammalian populations like humans.' But the textbooks on plant genetics are now due for revision in any case.
INFORMATION:
Further information
Dr. Frank Johannes; Groningen Bioinformatics Centre (GBiC), Groningen Biomolecular and Biotechnology Institute (GBB), Rijksuniversiteit Groningen; tel. +31 (0) 50 363 8079, e-mail f.johannes@rug.nl; http://www.johanneslab.org.
Article in Science Express, 7 February 2014: Mapping the Epigenetic Basis of Complex Traits
Revolutionary new view on heritability in plants
2014-02-11
ELSE PRESS RELEASES FROM THIS DATE:
How to make the wonder material graphene superconducting
2014-02-11
This news release is available in German.
Whenever a new material is discovered, scientists are eager to find out whether or not it can be superconducting. This applies particularly to the wonder material graphene. Now, an international team around researchers at the University of Vienna unveiled the superconducting pairing mechanism in Calcium doped graphene using the ARPES method. Their results are published in the reputed journal Nature Communications.
Superconducting materials exhibit an invaluable feature when cooled below a critical temperature – they allow ...
Acidic tumor pH inhibits drug effect
2014-02-11
Low pH in tumours counteracts the desired effect of the drug chloroquine, according to a new study from Karolinska Institutet in Sweden. The results, which are published in the journal Autophagy, might explain possible lack of efficacy of chloroquine in clinical studies.
Chloroquine, a widely used antimalaria drug, is currently under investigation in clinical trials on cancer patients. It is the ability of chloroquine to inhibit autophagy in tumour cells that has piqued researchers' interest. Autophagy is a homeostatic process by which cells eat parts of themselves, ...
Recent decades likely wettest in 4 millennia in Tibet
2014-02-11
Recent decades may have been the wettest in 3,500 years in North East Tibet – according to climate researchers at the University of East Anglia (UK) and the Chinese Academy of Sciences (Lanzhou, China).
Researchers looked at 3,500-year-long tree ring records from North East Tibet to estimate annual precipitation. They found that recent decades have likely been the wettest on record in this semi-arid region.
The precipitation records have been reconstructed using sub-fossil, archaeological and living juniper tree samples from the north-eastern Tibetan Plateau. They reveal ...
Walking in their shoes: How fundraisers can boost donations
2014-02-11
When natural disaster strikes, calls for help are broadcast on television and across the Internet. Despite being exposed to the needs of widespread relief organizations, only a small percentage of us actually follow through by making a financial contribution. According to a new study in the Journal of Consumer Research, the more connected we feel with the people needing our help, the more likely we are to donate.
"Our thought is that people who act more independently might not necessarily be more benevolent than people who are more connected to others within their own ...
Helical electron and nuclear spin order in quantum wires
2014-02-11
Physicists at the University of Basel have observed a spontaneous magnetic order of electron and nuclear spins in a quantum wire at temperatures of 0.1 kelvin. In the past, this was possible only at much lower temperatures, typically in the microkelvin range. The coupling of nuclei and electrons creates a new state of matter whereby a nuclear spin order arises at a much higher temperature. The results are consistent with a theoretical model developed in Basel a few years ago, as reported by the researchers in the scientific journal Physical Review Letters.
The researchers, ...
Dressing down: Can this actually boost your social status?
2014-02-11
From wearing a suit to a wedding to donning a tie for a job interview, American society has established unspoken rules for dress codes and proper etiquette. But there's always that one guy who wears the bright socks or the obnoxious bow tie. According to a new study in the Journal of Consumer Research, this type of behavior has the potential to increase a person's perceived success.
"We proposed that, under certain conditions, nonconforming behaviors can be more beneficial to someone than simply trying to fit in. In other words, when it looks deliberate, a person can ...
Are you a high achiever? Even the best products might leave you dissatisfied
2014-02-11
Make the honor roll, go for the promotion, or try the tastiest entrée on the menu. In almost every facet of our culture, we are told to "go for the gold." So, why settle for "good enough" when "something better" is within reach? According to a new study in the Journal of Consumer Research, constantly striving for the best may be magnifying negative feelings like regret and dissatisfaction in other parts of our daily lives.
"We found that individuals who have a 'must have the best' mindset experience more regret and are less satisfied with the products they purchase or ...
What is the safest way to stop postmenopausal hormone therapy?
2014-02-11
New Rochelle, NY, February 11, 2013—When the time comes for postmenopausal women to discontinue hormone therapy (HT), little is known about the best way to do so with minimal symptoms. A new study that explores optimal approaches to manage symptoms such as trouble sleeping, mood swings, and depression on discontinuation of HT is published in Journal of Women's Health, a peer-reviewed publication from Mary Ann Liebert, Inc., publishers. The article is available free on the Journal of Women's Health website at http://www.liebertpub.com/jwh.
Many women will try and fail ...
Males and females differ in specific brain structures
2014-02-11
Reviewing over 20 years of neuroscience research into sex differences in brain structure, a Cambridge University team has conducted the first meta-analysis of the evidence, published this week in the prestigious journal Neuroscience and Biobehavioral Reviews.
The team, led by doctoral candidate Amber Ruigrok and Professors John Suckling and Simon Baron-Cohen in the Department of Psychiatry, performed a quantitative review of the brain imaging literature testing overall sex differences in total and regional brain volumes. They searched all articles published between ...
YOLO: Aging and the pursuit of happiness
2014-02-11
As human beings, we expend a great deal of time, money, and energy in the pursuit of happiness. From exotic travel to simply spending time with our grandchildren, the things that make us happy change as we age. A new study in the Journal of Consumer Research explores the role of age on the happiness we receive from both the ordinary and the extraordinary experiences in our lives.
"We examine how age—and the perceived amount of time left in life—impacts the happiness people enjoy from both extraordinary and ordinary life experiences," write authors Amit Bhattacharjee ...