The way to learn
News Jan 25, 2016
Smart songbird's reference genome is milestone for research -
A well-known songbird, the great tit, has revealed its genetic code, offering researchers new insight into how species adapt to a changing planet. Their initial findings suggest that epigenetics—what's on rather than what's in the gene—may play a key role in the evolution of memory and learning. And that's not just true for birds. An international research team led by the Netherlands Institute of Ecology (NIOO-KNAW) and Wageningen University publishes these findings in Nature Communications today (Jan. 25).
"People in our field have been waiting for this for decades," explain researchers Kees van Oers and Veronika Laine from NIOO-KNAW. The reference genome of their favorite model species, the great tit, is "a powerful toolbox that all ecologists and evolutionary biologists should know about."
Coming from a single Dutch bird, the genetic code of the assembled reference genome will help to reveal the genetic basis of phenotypic evolution. This is essential for understanding how wild species adapt to our changing planet.
In addition to looking at the genome, the research team have also determined the so-called transcriptome and methylome. The latter belongs to the field of epigenetics: the study of what you can inherit not in but 'on' your genes. When specific DNA sequences in the genome are methylated, this modifies how the genes function.
The research team sequenced the complete genomes of a further 29 great tit individuals from different parts of Europe. This enabled them to identify regions in the great tit's genome that have been under selection during recent evolution of the bird. These regions appeared to be overrepresented for genes related to learning and cognition.
"The great tit has evolved to be smart," says Van Oers. "Very smart." It's not your average bird, as it belongs to the top 3% smartest birds when it comes to learning new behavior. That makes it a perfect candidate for research into the evolution of learning, memory and cognitive processes.
What that research has revealed are so-called conserved patterns of methylation in those same regions, present not only in birds but also in humans and other mammals. It's evidence of a correlation between epigenetic processes such as methylation and the rate of molecular evolution: "the more methylation, the more evolution."
And so the great tit has once more proved that its role as a model species in a variety of biological research fields for over 60 years is by no means coincidental.
Note: Material may have been edited for length and content. For further information, please contact the cited source.
Laine VN et al. Evolutionary signals of selection on cognition from the great tit genome and methylome. Nature Communications, Published Online January 25 2016. doi: 10.1038/ncomms10474
Adult depression has long been associated with shrinkage of the hippocampus, a brain region that plays an important role in memory and response to stress. Now, new research has linked participation in team sports to larger hippocampal volumes in children and less depression in boys ages 9 to 11.
Researchers have discovered a brain process common to sleep and ageing in research that could pave the way for new treatments for insomnia. The scientists report how oxidative stress leads to sleep. Oxidative stress is also believed to be a reason why we age and a cause of degenerative diseases.READ MORE
Patients in a new Northwestern Medicine study were able to comprehend words that were written but not said aloud. They could write the names of things they saw but not verbalize them. This provides an insight into the brain degeneration that defines the rare dementia termed primary progressive aphasia.