Researchers found a higher prevalence of the influence of so-called positive selection on genes or gene regions known to be associated with the disorder than a comparable control set of non-associated genes, functioning in similar neuronal processes.
This is consistent with the theory that positive selection may play a role in the persistence of schizophrenia at a frequency of one per cent in human populations around the world, despite its strong effects on reproductive fitness and its high heritability from generation-to-generation.
It also provides genetic evidence consistent with the long-standing theory that schizophrenia represents, in part, a maladaptive by-product of adaptive changes during human evolution - possibly to do with aspects of creativity and human cognition.
“The world-wide presence of this disorder at an appreciable frequency, despite its impact on human health and reproductive fitness, is somewhat of a paradox,” said Dr Steve Dorus from the University of Bath, who worked with Dr Bernard Crespi from Simon Fraser University (Canada) and Dr Kyle Summers from East Carolina University (USA) on the research.
“This may be explained by the existing theory that the condition represents, in part, a by-product of adaptive changes during human evolution.
“Our finding that positive evolutionary processes have impacted genes underlying the disorder is consistent with this idea.
“However, the selective forces influencing the evolution of these genes remain unknown.
“Given the complex genetic nature of the condition, selection may be mediated by a diverse array of neurodevelopmental, neurophysiological and psychological mechanisms.
“Schizophrenia has also been associated with creativity throughout recorded history, but whether this link has a genetic basis is certainly not yet clear.”
The researchers analysed the molecular evolution of the 76 genes that have the strongest genetic association with the disorder.
They surveyed human polymorphisms - discrete changes in the human genome that vary between individuals - for very recent selective events within specific human populations.
They also compared genes between mammalian species to identify selection on primate lineages salient to the evolution of humans and the disorder.
The research identified evidence for positive selection on a variety of genes, including three genes that have the best functional or reproducible associations with the disorder: disrupted in schizophrenia (DISC1), dystrobrevin-binding protein 1 (DTNBP1) and neuregulin 1 (NRG1).
“For the first time it is possible to complement our genetic understanding of the disorder with substantial evolutionary and comparative genomic analyses,” said Dr Dorus.
“Decades of intensive research, using association and inheritance studies between affected and non-affected siblings, has resulted in a much clearer understanding of the genetic basis of the disorder.
“Hopefully, a better understanding of the evolution of the substrates underlying the disease will assist in characterizing how they are dysregulated in the disorder.
“Understanding the impact of positive selection may also help refine hypotheses concerning genetic links between schizophrenia and aspects of human creativity and cognition."
The research was funded in part by the Natural Sciences and Engineering Research Council of Canada, East Carolina University and the National Institutes of Health.
Andrew McLaughlin | alfa
During HIV infection, antibody can block B cells from fighting pathogens
14.08.2018 | NIH/National Institute of Allergy and Infectious Diseases
First study on physical properties of giant cancer cells may inform new treatments
14.08.2018 | Brown University
Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.
When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...
Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.
Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....
Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.
Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...
Scientists have discovered that the electrical resistance of a copper-oxide compound depends on the magnetic field in a very unusual way -- a finding that could help direct the search for materials that can perfectly conduct electricity at room temperatur
What happens when really powerful magnets--capable of producing magnetic fields nearly two million times stronger than Earth's--are applied to materials that...
The quality of materials often depends on the manufacturing process. In casting and welding, for example, the rate at which melts solidify and the resulting microstructure of the alloy is important. With metallic foams as well, it depends on exactly how the foaming process takes place. To understand these processes fully requires fast sensing capability. The fastest 3D tomographic images to date have now been achieved at the BESSY II X-ray source operated by the Helmholtz-Zentrum Berlin.
Dr. Francisco Garcia-Moreno and his team have designed a turntable that rotates ultra-stably about its axis at a constant rotational speed. This really depends...
08.08.2018 | Event News
27.07.2018 | Event News
25.07.2018 | Event News
14.08.2018 | Information Technology
14.08.2018 | Life Sciences
14.08.2018 | Life Sciences