In this week’s issue of Nature, an international team led by Junjie Qin of the BGI in Shenzhen, China, reports their metagenomic sequencing and analysis of the human gut microbiome. Using an Illumina platform, the team sequenced and assembled 3.3 million non-redundant microbial genes from fecal samples of 124 European individuals, representing a gene set about “150 times larger than the human gene complement.” Qin et al. found that more than 99 percent of the genes were bacterial, and that they were largely shared among individuals in the cohort.
In a letter appearing in Nature Biotechnology this week, researchers in New York write that hESC-derived endothelial cell maintenance by TGFβ inhibition is Id1 dependent. Using an endothelial cell-specific VE-cadherin promoter driving GFP, the team was able to screen for factors that promote vascular commitment. Then, by using a reporter line, the team was able to show that Id1 is required for increased proliferation and commitment of hESC-derived endothelial cells. “Our approach provides a serum-free method for differentiation and long-term maintenance of hESC-derived endothelial cells at a scale relevant to clinical application,” the authors write.
Another article appearing online this week reports a continuum of binding affinities wherein multisite post-translational modification recognition “involves both switch- and rheostat-like properties, yielding graded effects that depend on the inherent ‘reader’ specificity.” Using mass spectrometric, NMR, and antibody-based techniques, a team of researchers interrogated the specificity of six chromatin binding molecules. They found that Thr3 and Trh6 phosphorylation, as well as Arg2 methylation are critical post-translational modifications which regulate the ability to recognize and bind histone H3.
An advance publication of a paper in Nature Genetics communicates a second-generation GWAS which identified multiple common variants for celiac disease that influence immune gene expression. A large collaborative team examined 4,533 cases of the autoimmune disease and 10,750 controls. From there, the researchers genotyped specific SNPs; they found variants from 13 regions which reached genome-wide significance.