In PLOS Genetics, investigators in Germany and the US outline population structures identified with whole-genome sequences for individuals from more than a dozen populations from around the world. The team came up with a computational strategy based on an existing Multiple Sequentially Markovian Coalescent approach to explore population histories, relationships, and diversification features in 15 global populations, using whole-genome sequences generated for the Simons Genome Diversity Project. "Among other results, we find evidence for remarkably deep population structure in some African population pairs," the authors report, "suggesting that deep ancestry dating to one million years ago and older is still present in human populations in small amounts today."
Researchers from Spain look at the relationship between malignant melanoma progression and mutational loads related to BRAF V600E mutations for a paper in PLOS One. The team used digital PCR to assess BRAF V600E mutational load in 78 melanoma biopsies and a handful of atypical mole samples, uncovering mutational load differences that appeared to coincide with tumor stage. That prompted follow up analyses suggesting that BRAF V600E mutational load might serve as a predictor for progression and metastasis in stage II melanoma. "The great variability of BRAF V600E mutational load observed in the samples analyzed, highlights the fact that tumor heterogeneity is a common feature in melanoma, where several sub-clones can exist," the authors write, calling BRAF V600E "a promising biomarker of prognosis … which may help to improve the personalized medical care and survival of melanoma patients."
An international team led by investigators at the Pan American Health Organization explores influenza virus evolution in Latin America for another PLOS One study. Using targeted gene sequencing on hundreds of influenza A and influenza B clinical samples collected at a dozen national influenza centers in Mexico, Central America, and South America in 2017 and 2018, the researchers tracked influenza virus evolution and phylogenetic relationships, compiling the data on the Global Initiative on Sharing All Influenza Data (GISAID) database. "Considering the constant evolution of influenza viruses," they report, "high quality surveillance data — specifically genetic sequence data — are important to allow public health decision makers to make informed decisions about prevention and control strategies, such as influenza vaccine composition."