In this week's Nature, a group led by Max Planck researchers reports data from an analysis of nuclear DNA isolated from hominins from northern Spain, providing new insights into hominin evolution. An earlier study using mitochondrial DNA from the specimens indicated that they had a closer relationship to Denisovans living in Asia in the Late Pleistocene than to Neanderthals, contrary to archeological evidence. By combining sample isolation and genome sequencing technologies, the researchers extracted and analyzed nuclear DNA from the hominins, as well as mitochondrial DNA. The nuclear DNA shows that the hominins belong to the Neanderthal evolutionary lineage, and suggests a closer relationship with Neanderthals than with Denisovans. It also points to population divergence between Neanderthals and Denisovans more than 430,000 years ago. GenomeWeb has more on this study here.
And in Nature Neuroscience, an international team of scientists presents their discovery of rare mutations in a single gene that significantly increases the risk of schizophrenia. They sequenced the protein-coding regions of the genomes of 8,534 individuals with and without schizophrenia from British and Finnish populations, then combined the results with existing data from studies of more than 6,000 other individuals both with and without the disease. They discovered SETD1A, a gene that regulates changes to chromosomes that control gene expression, was the only gene across the entire genome that had more deleterious mutations in people with schizophrenia. The Scan has more on this paper here.
Finally, in Nature Genetics, a group of German scientists publish a study indicating that non-genetic factors may play a role in inherited diet-induced obesity. They fed genetically identical mice a high-fat, low-fat, or normal diet for six weeks. Animals receiving the high-fat diet developed obesity and glucose intolerance, as expected. The researchers then produced embryos using sperm and eggs from mice fed different diets and implanted them in healthy surrogate mothers in order to separate environmental factors from epigenetic ones in the sperm and eggs. The adult offspring were then placed on a high-fat diet. The team found that offspring with two obese parents gained significantly more weight on a high-fat diet than those with only one obese parent. Offspring of two lean parents gained the least weight on a high-fat diet, and similar trends were seen in relation to glucose intolerance. The findings indicate that epigenetic factors in gametes may have a key role the transmission of obesity and diabetes risk from parent to child.