In this week's Science, an international research team presents data highlighting the role of random errors in DNA replication in cancer. The scientists analyzed genome sequencing and epidemiologic data from 32 cancer types and found that two-thirds of mutations in these cancers were due to random errors that occur in normal dividing cells during DNA replication, rather than hereditary or environmental causes. In a second analysis that included data generated in 69 countries, the researchers confirmed a high correlation between cancer incidence and the total number of divisions in normal stem cells that they had previously reported based on data from a US-only population. "All of these results are consistent with epidemiological estimates of the fraction of cancers that can be prevented by changes in the environment," the investigators write, and underscore the importance of early detection and intervention to reduce deaths caused by unavoidable DNA replication errors. GenomeWeb has more on this here.
Also in Science, a Baylor College of Medicine-led group of scientists report the use of a new technique to generate high-quality genome assemblies of the human genome and of the mosquito disease vectors Aedes aegypti and Culex quinquefasciatus genomes. They combined Hi-C data with existing draft assemblies to generate chromosome-length scaffolds, then applied this method to draft sequences to create the genome assemblies — the mosquito ones each consisted of three scaffolds corresponding to the three chromosomes in each species. The procedure is fast, inexpensive, accurate, and applicable to many other species, the researchers note. GenomeWeb also covers this here.