NATURE METHODS | VOL.11 NO.11 | NOVEMBER 2014 IN THIS ISSUE software tool that bins genomic fragments that have Improving tools for synthetic first undergone limited preassembly into contigs. biology Their strategy uses a variational Bayesian approach combining sequence composition and correlated To rapidly and reliably engineer biological abundance across multiple samples to produce networks—one of the promises of synthetic sequence assignments. CONCOCT bins genomes with biology—a larger repertoire of regulatory high precision and recall in simulated and real data, elements and better characterization of their providing higher coverage than can typically be performance are needed. Two groups now deliver reached by single-cell sequencing. on each of these aspects. Smolke and colleagues Brief Communication p1144 present a model to predict the expression of a target gene that is regulated by a microRNA and then extend the model to anticipate the High-throughput single protein behavior of genetic circuits that use protein- responsive microRNA switches to detect the pulling concentration of a nuclear protein in mammalian One of the main technical challenges in making cells. Fussenegger and colleagues create a library single-molecule force spectroscopy measurements of protein-responsive ribozymes for translational control and then design a three-input AND gate has been the method’s low-throughput nature, which in mammalian cells that combines transcriptional has precluded the screening of large protein-variant and translational control. libraries. Nash and colleagues now describe a system Articles p1147, p1154, News and Views p1105 that readily enables thousands of protein pulling measurements. They begin with a microspotted DNA array and synthesize proteins in situ with the aid of A deeper look at proteogenomics microfluidics-based cell-free expression technology. Each protein is labeled with a common dockerin In a traditional shotgun mass spectrometry–based tag, which then enables on-chip high-throughput proteomics approach, experimental peptide mass single-molecule force spectroscopy measurements by spectra are identified by comparison to theoretical pulling on individual, tagged proteins with a cohesin- spectra generated from peptides present in reference modified cantilever. The method brings research in protein databases. A limitation with this approach the single-molecule field one step closer to large- is that discovery of new peptides—including scale screening of protein nanomechanical properties. alternatively spliced forms, novel protein-coding Brief Communication p1127 Nature America, Inc. All rights reserved. America, Inc. Nature loci and disease-related mutant peptides—is 4 not possible. A relatively new way of identifying such peptides, known as proteogenomics, is thus Backpack recorders for zebra © 201 gathering steam. In a proteogenomics approach, finches genomic or transcriptomic data are used to construct a customized protein database to aid Anyone who has npg in finding novel peptides not present in reference tried to keep up a databases. Nesvizhskii discusses the fundamentals conversation in a noisy of proteogenomics technology and its applications place can appreciate in a Review, providing practical advice about the the difficulty of proper usage of statistical methods to avoid false recording individual positive results. In a Perspective, Boutros, Kislinger voices in a crowded A. Victor and colleagues make a strong case for applying a social environment. proteogenomics approach to study cancer biology. Vyssotski and colleagues now address the problem Perspective p1107, Review p1114 of distinguishing one voice among the flock with the development of recording devices that zebra finches can carry as backpacks. Each backpack Genomes from metagenomic data weighs about 3 grams and contains a small microphone, an accelerator and electronic hardware. Assembling microbial genomes from short sequenced Whereas the microphone records all sound in the DNA fragments is a challenge, but the difficulty environment, the accelerator registers only the multiplies when the sequence pool is a mixture of vibrations generated by the bird’s own vocalizations. unknown microbial flora. A key step in reducing this The researchers use the backpack song recorders complexity is to assign, or ‘bin’, sequence fragments to analyze vocal interactions in pairs of birds in according to the species or strain genome from which the lab, but it should also be possible to use the they originate. Here Quince, Andersson and colleagues recording devices in the wild. develop CONCOCT, an open-source unsupervised Brief Communication p1135.