Researchers from the universities of Calgary and Cambridge, UK, have discovered that a mutation in a gene necessary for the metabolism of folic acid not only impacts immediate offspring but can also have detrimental health effects, such as spina bifida and heart abnormalities, on subsequent generations.
The animal study, published this week in the journal Cell, also sheds light on the molecular mechanism of folic acid (also known as folate) during development.
About one in 1,200 children are born with spina bifida. The detrimental effects of folic acid deficiency during pregnancy on development are well known. As a result Canada, and many other countries, have implemented folate fortification programs which require folic acid to be added to cereal products. The aim has been to reduce the incidence of developmental problems, including spina bifida. However, until now, very little was known about how folic acid deficiency caused the diverse range of health problems in offspring.
"Fortification programs have reduced the risk of health effects but not eliminated them completely," says Dr. Jay Cross, with the faculties of medicine and veterinary medicine. "Based on our research, we now believe that it may take more than one generation to eliminate the health problems caused by folate deficiency. In addition, we need to be thinking not just about our own genes and how they impact our health and development, but also those of our descendents."
Cross, also a member of the Alberta Children's Hospital Research Institute, co-authored the study with Dr. Erica Watson from the University of Cambridge. Watson is a University of Calgary alumna and started the work during her PhD studies with Cross before moving to Cambridge.
Researchers from the university used mice for the study because their folic acid metabolism is very similar to humans. This enabled the researchers to explore how the molecular mechanism of folic acid deficiency impacted development, thereby causing developmental problems.
Dr. Roy Gravel, also a co-author of the study and member of the Alberta Childrens' Hospital Research Institute says this study provides a tremendous opportunity to look at the prevention of diseases like spina bifida. "The work began as a study of a gene called Mtrr in mice. The goal was to shed light on how a mutation in Mtrr would affect folate metabolism. The multigeneral effect we observed was completely unexpected," says Gravel.
The Mtrr gene encodes an enzyme that is key to the metabolism of folic acid and, when mutated, causes similar effects to dietary folic acid deficiency. The researchers found that when either the maternal grandmother or the maternal grandfather had this Mtrr mutation, their genetically normal grandchildren were at risk of a wide spectrum of developmental abnormalities, even if the mutated gene was not inherited through to the next generations.
These developmental abnormalities were also seen in the fourth and fifth generations of mice.
Through a series of experiments, researchers discovered that the developmental abnormalities were not passed down genetically. Instead, the defects were the result of "epigenetic" changes, which had been inherited. Epigenetics is a process which turns genes on and off through chemical modifications to DNA without changing the genetic code itself. Epigenetic inheritance refers to the passing along of these epigenetic marks as cells divide during development. It had been previously thought that epigenetic modifications were, for the most part, 'wiped clean' after each generation.
The researchers hypothesize that, for a yet unknown reason, some of these abnormal epigenetic marks caused by the Mtrr mutation escape this normal erasure and are inherited by the next generation. If the abnormal epigenetic marks that regulate genes important for development are inherited, then these generations may develop abnormalities as a result of the wrong genes being turned on or off.
"There have been several recent studies implicating folate in different types of human diseases, not just developmental abnormalities, and so our work provides insights into potential biochemical mechanism but also adds a layer of complexity in thinking about transgenerational effects of folate," says Cross.
"This was a very complex study and initially controversial for some. As a result, we could not have accomplished this work without key collaborations both here in Calgary and Cambridge."
The research for this study was supported by grants from the Canadian Institutes of Health Research and Alberta Innovates-Health Solutions.
Media ContactGloria Visser-Niven
For more information, visit ucalgary.ca. Stay up to date with University of Calgary news headlines on Twitter @UCalgary and in our media centre at ucalgary.ca/news/media.
Gloria Visser-Niven | EurekAlert!
Correct connections are crucial
26.06.2017 | Charité - Universitätsmedizin Berlin
One gene closer to regenerative therapy for muscular disorders
01.06.2017 | Cincinnati Children's Hospital Medical Center
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
26.06.2017 | Life Sciences
26.06.2017 | Physics and Astronomy
26.06.2017 | Information Technology