Members of the Human Induced Pluripotent Stem Cells Initiative present a detailed look at the genetic and phenotypic variability in human induced pluripotent stem cells (iPSCs). They generated, genotyped, and phenotyped 711 iPSC lines derived from 301 healthy individuals, identifying the major sources of genetic and phenotypic variation in these cells and establishing their suitability as models of complex human traits and cancer. Using genome-wide profiling, the scientists found that between 5 and 46 percent of the variation in different iPSC phenotypes arises from differences in individuals. They also assessed the phenotypic consequences of rare genomic copy number mutations observed in iPSC reprogramming, and provide a map of common regulatory elements affecting the human pluripotent cell transcriptome.
In Nature Genetics, a research team led by scientists from the University of Helsinki presents a genomic analysis of the silver birch, a boreal tree with significant commercial value that can be induced to flower within one year. The scientists sequenced the genomes of 80 of the trees, sampling populations throughout its range, and identified a number of genetic mutations, including ones related to growth and wood production. They also uncovered selective sweeps that appear to be linked to environmental conditions. The findings may have practical relevance for forest biotechnology, the authors state.
Meanwhile, in Nature Medicine, a multi-institute team published a mutational landscape of metastatic cancer based on sequence data from a cohort of more than 10,000 patients. To do so, the scientists used a hybridization capture-based next-generation sequencing panel — developed at Memorial Sloan Kettering Cancer Center — that is capable of detecting all protein-coding mutations, copy number alterations, and selected promoter mutations and structural rearrangements in hundreds of cancer-associated genes. They identified clinically relevant somatic mutations, novel noncoding alterations, and mutational signatures that were shared by common and rare tumor types, and have made all the data publicly available.