In Nature this week, researchers from the University of California, Berkeley reported on an ancient genetic variation that enables Tibetans to survive at high altitudes. The low oxygen levels on the Tibetan plateau make it inhospitable to most humans except those indigenous people. Previous studies have identified a hypoxia pathway gene called EPAS1 as being key to Tibetans' ability to live in this environment. To study this further, the scientists re-sequenced the region around EPAS1 in 40 Tibetan and 40 Han Chinese individuals, finding that this gene probably came from the introduction of DNA from a group of ancient humans called Denisovans. Screening a larger set of worldwide populations reveals that the DNA sequence is only found in Tibetans and Denisovans, and, at lower frequencies, in Han Chinese.
Meanwhile, in Nature Genetics, members of The Genome of the Netherlands Consortium presented the genomic sequences of 250 Dutch families — the largest such collection from a single country. The scientists sequenced 769 Dutch genomes from 250 groups of parents and offspring. Among their major findings were 7.6 million variants in the genome that had never before been observed. They also found that each person in the study carried, on average, eight rare gene mutations that could lead to disease.
And in Nature Methods, an international team of academic and industry researchers this week published the results of a comparison of commercially available platforms for microRNA expression analysis, finding that each has its own strengths and shortcomings that should be considered before selecting one for a particular study.