French Jura flor yeasts: genotype and technological diversity

Fifty-four Saccharomyces cerevisiae strains were isolated from Jura “Vin Jaune” velum and characterized by conventional physiological and molecular tests including ITS RFLP and sequence analysis, karyotyping and inter delta typing. ITS RFLP and sequence revealed a specific group of related strains different from the specific profile of Sherry flor yeast caused by a 24 bp deletion in the ITS1 region described by Esteve-Zarzoso et al. (Antonie Van Leeuwenhoek 85:151–158, 2004). Interdelta typing, the most discriminative method, revealed a high diversity of Jura flor yeast strains and gathered strains in clusters unequally shared between the northern and southern part of the Jura vineyard. The assessment of phenotypic diversity among the isolated strains was investigated for three wine metabolites (ethanal, acetic acid, and sotolon) from micro scale velum tests. Except at an early stage of ageing, the production of these metabolites was not correlated to the five genetic groups obtained by interdelta typing, but correlated to the cellar where strains had been isolated. The different strains isolated in a cellar produced mostly one type of velum (thin or thick, grey or white); but thin and grey velums, recognized as responsible for high quality wines, were obtained more frequently for one of the five groups of delta genotypes.     

Integrating social science and genetics: news from the political front

There has been growing interest in the use of genetic models to expand the understanding of political preferences, attitudes, and behaviors. Researchers in the social sciences have begun incorporating these models and have revealed that genetic differences account for individual differences in political beliefs, behaviors, and responses to the political environment. The first Integrating Genetics and the Social Sciences Conference, held at Boulder, Colorado in May of 2010, brought together these researchers. As a result, we jointly review the last 5 years of research in this area. In doing so, we explicate the methods, findings, and limitations of behavior genetic approaches, including twin designs, association studies, and genome-wide analyses, in their application toward exploring political preferences.     

Global and regional tree species diversity

Aims Understanding tree species richness at a global scale and the origin and maintenance of patterns of tree species richness across the world is crucial to preserving tree species diversity. The recently published global tree database (i.e. GlobalTreeSearch) is the only source with tree lists at both global and national scales. However, our review and assessment show that many species included in GlobalTreeSearch are not tree species. In addition, several thousands of tree species in the botanical literature have not been included in GlobalTreeSearch. The exact number of tree species in the world remains unknown. This study aims to correct errors with GlobalTreeSearch and to estimate the number of tree species in the world based on a large number of regional floras.     

Quantitative partitioning of regional and local processes shaping regional diversity patterns

Much recent research explaining plant community diversity has focused on comparing the relative impacts of regional and local processes. We employed a novel analysis to quantify the effects of multiple regional and local processes on species richness, and to make quantitative comparisons of those effects across two sites that differ in plot-level species richness, productivity and environmental conditions. While abiotic stress and competition limited richness within the communities at both sites, only differences in the overall pool of species at the site, likely resulting from long-distance dispersal and climate fluctuations, explained the differences in plot-level richness between sites. Patterns in local richness may be driven by a temporal storage effect, with greater richness in the site with greater climatic variability. By identifying both the factors that impact diversity within communities and those that vary systematically across communities, our integrated approach provides a better understanding of regional diversity patterns.     

A CRISPR-based strategy for targeted sequencing in biodiversity science

Many applications in molecular ecology require the ability to match specific DNA sequences from single- or mixed-species samples with a diagnostic reference library. Widely used methods for DNA barcoding and metabarcoding employ PCR and amplicon sequencing to identify taxa based on target sequences, but the target-specific enrichment capabilities of CRISPR-Cas systems may offer advantages in some applications. We identified 54,837 CRISPR-Cas guide RNAs that may be useful for enriching chloroplast DNA across phylogenetically diverse plant species. We tested a subset of 17 guide RNAs in vitro to enrich plant DNA strands ranging in size from diagnostic DNA barcodes of 1,428 bp to entire chloroplast genomes of 121,284 bp. We used an Oxford Nanopore sequencer to evaluate sequencing success based on both single- and mixed-species samples, which yielded mean chloroplast sequence lengths of 2,530–11,367 bp, depending on the experiment. In comparison to mixed-species experiments, single-species experiments yielded more on-target sequence reads and greater mean pairwise identity between contigs and the plant species' reference genomes. But nevertheless, these mixed-species experiments yielded sufficient data to provide ≥48-fold increase in sequence length and better estimates of relative abundance for a commercially prepared mixture of plant species compared to DNA metabarcoding based on the chloroplast trnL-P6 marker. Prior work developed CRISPR-based enrichment protocols for long-read sequencing and our experiments pioneered its use for plant DNA barcoding and chloroplast assemblies that may have advantages over workflows that require PCR and short-read sequencing. Future work would benefit from continuing to develop in vitro and in silico methods for CRISPR-based analyses of mixed-species samples, especially when the appropriate reference genomes for contig assembly cannot be known a priori.     

The consequences of political dictatorship for Russian science

The Soviet communist regime had devastating consequences on the state of Russian twentieth century science. Country Communist leaders promoted Trofim Lysenko--an agronomist and keen supporter of the inheritance of acquired characters--and the Soviet government imposed a complete ban on the practice and teaching of genetics, which it condemned as a "bourgeois perversion". Russian science, which had previously flourished, rapidly declined, and many valuable scientific discoveries made by leading Russian geneticists were forgotten.     

A trace of silence: memory and microRNA at the synapse

Identifying the neural circuits that mediate particular behaviors and uncovering their plasticity is an endeavor at the heart of neuroscience. This effort is allied with the elucidation of plasticity mechanisms, because the molecular determinants of plasticity can be markers for the neurons and synapses that are modified by experience. Of particular interest is protein synthesis localized to the synapse, which might establish and maintain the stable modification of neuronal properties, including the pattern and strength of synaptic connections. Recent studies reveal that microRNAs and the RISC pathway regulate synaptic protein synthesis. Is synaptic activity of the RISC pathway a molecular signature of memory?