In this week's Nature Biotechnology, an international research team reports the sequencing and de novo assembly of a human genome using Oxford Nanopore Technologies' MinION portable nanopore sequencer. The scientists used the device to sequence and assemble the GM12878 Utah/Ceph human cell line genome, producing 91.2 Gb of sequence data. They also developed a protocol to generate ultra-long reads of up to 882 kb each. The study demonstrates that "a portable, biological nanopore sequencer could be used to sequence, assemble, and provisionally analyze structural variants and detect epigenetic marks in point-of-care human genomics applications in the future," the authors write. The Scan also covers this, here.
In Nature Chemical Biology, a team of US and Russian scientists describe a technique for reducing the off-target effects of CRISPR-Cas9 genome editing. The investigators found that swapping some RNA nucleotides for DNA nucleotides in the guide sequence that directs Cas9 to its genomic destination can decrease off-target activity, while still retaining CRISPR efficacy. The results may provide "a generalized strategy to reduce both the cost and the off-target genome editing in human cells," the researchers note.
Meanwhile, in Nature Communications, a Christian Albrechts University-led group publishes a study showing that aging-associated gene expression changes follow trajectories similar to the those observed in degenerative aging diseases, but opposite of those observed in cancer. The scientists generated a dataset of transcriptomic alterations in humans, mice, zebrafish, and killifish at different ages across four tissue types. They found that aging-associated transcriptomic changes follow trajectories similar to the transcriptional alterations observed in degenerative diseases, but are in opposite direction to the transcriptomic alterations observed in cancer.The findings offer new insights into the transition from cancer to degenerative chronic disorders as dominant contributors to mortality in the old. They also confirmed a similar antagonism on the genomic level, "where a majority of shared risk alleles which increase the risk of cancer decrease the risk of chronic degenerative disorders and vice versa." GenomeWeb has more on this, here.