In Nature this week, a multi-institute team of scientists publishes a comprehensive analysis of somatic mutations across whole-genome sequences for breast cancer. They sequenced the full genomes of tumors and normal tissue from 560 breast cancer patients across both coding and non-coding regions, and identified several mutational signatures associated with defective DNA repair and tumor suppressor gene function. In a related paper in Nature Communications, the lead investigators used the same genomes to demonstrate that specific mutational signatures are associated with elements of genomic architecture. GenomeWeb has more on these studies, here.
Also in Nature, a group led by Harvard University researchers reports on a genetic analysis of Ice Age Europeans, providing insights into migration and population turnover among these prehistoric individuals and pointing to a new lineage of early modern humans. The investigators analyzed genome-wide data from 51 Eurasians who lived between 45,000 years and 7,000 years ago. They found that those who were the earliest to arrive to Europe contributed only a small amount of genetic variation to present-day Europeans, who can instead trace their ancestry to a group of humans who lived in northwest Europe around 35,000 years ago. While this founding population was displaced by another group of early humans, their descendants can be found in southwest Europe around 19,000 years ago and are believed to have repopulated Europe after the end of the Last Glacial Maximum. The study also finds that additional genetic variation in modern-day Europeans may have originated from the Near East, and that the amount of Neanderthal ancestry in modern Europeans has decreased over the last 45,000 years. GenomeWeb has more on this study, too, here.