DNA Tetrominoes: The Construction of DNA Nanostructures Using Self-Organised Heterogeneous Deoxyribonucleic Acids Shapes

The unique programmability of nucleic acids offers alternative in constructing excitable and functional nanostructures. This work introduces an autonomous protocol to construct DNA Tetris shapes (L-Shape, B-Shape, T-Shape and I-Shape) using modular DNA blocks. The protocol exploits the rich number of sequence combinations available from the nucleic acid alphabets, thus allowing for diversity to be applied in designing various DNA nanostructures. Instead of a deterministic set of sequences corresponding to a particular design, the protocol promotes a large pool of DNA shapes that can assemble to conform to any desired structures. By utilising evolutionary programming in the design stage, DNA blocks are subjected to processes such as sequence insertion, deletion and base shifting in order to enrich the diversity of the resulting shapes based on a set of cascading filters. The optimisation algorithm allows mutation to be exerted indefinitely on the candidate sequences until these sequences complied with all the four fitness criteria. Generated candidates from the protocol are in agreement with the filter cascades and thermodynamic simulation. Further validation using gel electrophoresis indicated the formation of the designed shapes. Thus, supporting the plausibility of constructing DNA nanostructures in a more hierarchical, modular, and interchangeable manner.     

No evidence for female kin association,indications for extragroup paternity,and sex‐biased dispersal patterns in wild western gorillas

Characterizing animal dispersal patterns and the rational behind individuals’ transfer choices is a long‐standing question of interest in evolutionary biology. In wild western gorillas (Gorilla gorilla), a one‐male polygynous species, previous genetic findings suggested that, when dispersing, females might favor groups with female kin to promote cooperation, resulting in higher‐than‐expected within‐group female relatedness. The extent of male dispersal remains unclear with studies showing conflicting results. To investigate male and female dispersal patterns and extragroup paternity, we analyzed long‐term field observations, including female spatial proximity data, together with genetic data (10 autosomal microsatellites) on individuals from a unique set of four habituated western gorilla groups, and four additional extragroup males (49 individuals in total). The majority of offspring (25 of 27) were sired by the group male. For two offspring, evidence for extragroup paternity was found. Contrarily to previous findings, adult females were not significantly more related within groups than across groups. Consistently, adult female relatedness within groups did not correlate with their spatial proximity inferred from behavioral data. Adult females were similarly related to adult males from their group than from other groups. Using R _ST statistics, we found significant genetic structure and a pattern of isolation by distance, indicating limited dispersal in this species. Comparing relatedness among females and among males revealed that males disperse farer than females, as expected in a polygamous species. Our study on habituated western gorillas shed light on the dispersal dynamics and reproductive behavior of this polygynous species and challenge some of the previous results based on unhabituated groups.     

Mycobiota in Portuguese 'normal' and 'green' cork throughout the manufacturing process of stoppers

The compounds responsible for the so-called 'cork taint' include, among others, some microbial metabolites which can be produced by the microbial population colonizing the unprocessed cork and stoppers. This study was intended to obtain information on the mycobiota associated with Portuguese cork throughout the manufacturing process of stoppers. Samples of barks and stoppers of both 'normal' and 'green' cork were examined. Moulds were isolated from 'normal' and 'green' cork throughout the entire cork stopper manufacturing process. Yeasts were rarely detected in the corks. Fungal contamination was not detected in finished stoppers from the company under study.     

Metabolic flux analysis of Escherichia coli expressing the Bacillus subtilis acetolactate synthase in batch and continuous cultures.

Metabolically engineered Escherichia coli expressing the B. subtilis acetolactate synthase has shown to be capable of reducing acetate accumulation. This reduction subsequently led to a significant enhancement in recombinant protein production. The main focus of this study is to systematically examine the effect of ALS in the metabolic patterns of E. coli in batch and continuous culture. The specific acetate production rate of a strain carrying the B. subtilis als gene is 75% lower than that of the control strain (host carrying the control plasmid pACYC184) in batch cultures. The ALS strain is further demonstrated to be capable of maintaining a reduced specific acetate production rate in continuous cultures at dilution rates ranging from 0.1 to 0.4 h-1. In addition, this ALS strain is shown to have a higher ATP yield and lower maintenance coefficient. The metabolic flux analysis of carbon flux distribution of the central metabolic pathways and at the pyruvate branch point reveals that this strain has the ability to channel excess pyruvate to the much less toxic compound, acetoin.     

Timer-based proteomic profiling of the ubiquitin-proteasome system reveals a substrate receptor of the GID ubiquitin ligase

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