Expressible molecular colonies

Carrying out polymerase chain reaction in a gel layer generates a 2-D pattern of DNA colonies comprising pure genetic clones. Here we demonstrate that transcription, translation and protein folding can be performed in the same gel. The resulting nucleoprotein colonies mimic living cells by serving as compartments in which the synthesized RNAs and proteins co-localize with their templates. Yet, due to the absence of penetration barriers, such a molecular colony display allows cloned genes to be directly tested for the encoded functions. Now, the results imply that virtually any manipulations with genes and their expression products can be accomplished in vitro

Non-Enzymatic Template-Directed Recombination of RNAs

RNA non-enzymatic recombination reactions are of great interest within the hypothesis of the “RNA world”, which argues that at some stage of prebiotic life development proteins were not yet engaged in biochemical reactions and RNA carried out both the information storage task and the full range of catalytic roles necessary in primitive self-replicating systems. Here we report on the study of recombination reaction occuring between two 96 nucleotides (nts) fragments of RNAs under physiological conditions and governed by a short oligodeoxyribonucleotide template, partially complementary to sequences within each of the RNAs. Analysis of recombination products shows that ligation is predominantly template-directed, and occurs within the complementary complex with the template in “butt-to-butt” manner, in 1- or 3- nts bulges or in 2–3 nts internal loops. Minor recombination products formed in the template-independent manner are detected as well

Restricting SBH Ambiguity via Restriction Enzymes

Abstract. The expected number of n-base long sequences consistent with a given SBH spectrum grows exponentially with n, which severely limits the potential range of applicability of SBH even in an error-free setting. Restriction enzymes (RE) recognize specific patterns and cut the DNA molecule at all locations of that pattern. The output of a restriction assay is the set of lengths of the resulting fragments. By augmenting the SBH spectrum with the target string’s RE spectrum, we can eliminate much of the ambiguity of SBH. In this paper, we build on [20] to enhance the resolving power of restriction enzymes. We give a hardness result for the SBH+RE problem, and supply improved heuristics for the existing backtracking algorithm. We prove a lower bound on the number restric-tion enzymes required for unique reconstruction, and show experimental results that are not far from this bound.

Gateways to the FANTOM5 promoter level mammalian expression atlas

The FANTOM5 project investigates transcription initiation activities in more than 1,000 human and mouse primary cells, cell lines and tissues using CAGE. Based on manual curation of sample information and development of an ontology for sample classification, we assemble the resulting data into a centralized data resource (http://fantom.gsc.riken.jp/5/). This resource contains web-based tools and data-access points for the research community to search and extract data related to samples, genes, promoter activities, transcription factors and enhancers across the FANTOM5 atlas. Electronic supplementary material The online version of this article (doi:10.1186/s13059-014-0560-6) contains supplementary material, which is available to authorized users

Cloning of RNA molecules in vitro.

A method for RNA amplification in an immobilized medium is described. The medium contains a complete set of nucleotide substrates and purified Q beta replicase, an enzyme capable of exponentially amplifying RNAs under isothermal conditions. RNA amplification in the immobilized medium results in the formation of separate 'colonies', each comprising the progeny of a single RNA molecule (a clone). The colonies were visualized by staining with ethidium bromide, by utilizing radioactive substrates, and by hybridization with sequence-specific labeled probes. The number and identity of the RNA colonies corresponded to that of the RNAs seeded. When a mixture of different RNA species was seeded, these species were found in different colonies. Possible implementations of this technique include a search for recombinant RNAs, very sensitive nucleic acid diagnostics, and gene cloning in vitro