Synthesis and cell-free cloning of DNA libraries using programmable microfluidics

Microfluidics may revolutionize our ability to write synthetic DNA by addressing several fundamental limitations associated with generating novel genetic constructs. Here we report the first de novo synthesis and cell-free cloning of custom DNA libraries in sub-microliter reaction droplets using programmable digital microfluidics. Specifically, we developed Programmable Order Polymerization (POP), Microfluidic Combinatorial Assembly of DNA (M-CAD) and Microfluidic In-vitro Cloning (MIC) and applied them to de novo synthesis, combinatorial assembly and cell-free cloning of genes, respectively. Proof-of-concept for these methods was demonstrated by programming an autonomous microfluidic system to construct and clone libraries of yeast ribosome binding sites and bacterial Azurine, which were then retrieved in individual droplets and validated. The ability to rapidly and robustly generate designer DNA molecules in an autonomous manner should have wide application in biological research and development.     

Patient Representation and Advocacy for Alzheimer Disease in Germany and Israel

This paper analyses self-declared aims and representation of dementia patient organizations and advocacy groups (POs) in relation to two recent upheavals: the critique of social stigmatization and biomedical research focusing on prediction. Based on twenty-six semi-structured interviews conducted in 2016–2017 with members, service recipients, and board representatives of POs in Germany and Israel, a comparative analysis was conducted, based on a grounded theory approach, to detect emerging topics within and across the POs and across national contexts. We identified a heterogeneous landscape, with the only Israeli PO focusing strongly on caretakers, whereas in Germany several POs claim to represent this patient collective. Shared aims of all POs were fighting social stigma, balancing the loss of patients’ individual autonomy, and the well-being of caretakers. By highlighting the emergence of new groups of dementia self-advocacy against the more traditional advocacy by others, this study highlights how advocacy and representation in the context of AD are embedded in the discursive context of stigmatization and revised disease conception. Future developments in early diagnosis and prediction of dementia, with more affected people likely to conduct dementia self-advocacy, might challenge existing representation structures even more.     

Digital PCR-Based Method for Detecting CDKN2A Loss in Brain Tumours

Molecular Diagnosis & Therapy - CDKN2A is a key tumour suppressor gene and loss of CDKN2A can be found in many tumours. In astrocytoma grade IV, CDKN2A is deleted in more than 50% of tumours....     

Sucrose promotes stem branching through cytokinin

Shoot branching is an important aspect of plant architecture because it substantially affects plant biology and agricultural performance. Sugars play an important role in the induction of shoot branching in several species, including potato (Solanum tuberosum L.). However, the mechanism by which sugars affect shoot branching remains mostly unknown. In the present study, we addressed this question using sugar-mediated induction of bud outgrowth in potato stems under etiolated conditions. Our results indicate that sucrose feeding to detached stems promotes the accumulation of cytokinin (CK), as well as the expression of vacuolar invertase (VInv), an enzyme that contributes to sugar sink strength. These effects of sucrose were suppressed by CK synthesis and perception inhibitors, while CK supplied to detached stems induced bud outgrowth and VInv activity in the absence of sucrose. CK-induced bud outgrowth was suppressed in vinv mutants, which we generated by genome editing. Altogether, our results identify a branching-promoting module, and suggest that sugar-induced lateral bud outgrowth is in part promoted by the induction of CK-mediated VInv activity.

Sugar-induced lateral bud outgrowth is promoted by the induction of cytokinin and vacuolar invertase activity.     

Tumor Reliance on Cytosolic versus Mitochondrial One-Carbon Flux Depends on Folate Availability

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Drivers of Population Structure of the Bottlenose Dolphin (Tursiops truncatus) in the Eastern Mediterranean Sea

Evolutionary Biology - The drivers of population differentiation in oceanic high dispersal organisms, have been crucial for research in evolutionary biology. Adaptation to different environments is...     

Dissection of the faint little ball (flb) phenotype: determination of the development of the Drosophila central nervous system by early interactions in the ectoderm.

The complex embryonic phenotype of mutations in the faint little ball (flb) locus, encoding the Drosophila EGF receptor homolog (DER), was dissected by temperature shifts of a temperature-sensitive allele. We show that the phenotype can be resolved into at least five components, which are temporally and spatially distinct. Most notably, the central nervous system (CNS) phenotype is determined at two separate phases. A severe collapse results from early defects in the DER-expressing ectodermal cells from which neuroblasts and midline glial cells deaminate. We thus suggest that DER activity is crucial for interactions that occur in the ectoderm at an early stage, and determine the fate of neuronal and glial cell lineages. This finding explains how a severe CNS phenotype is generated in flb embryos, in spite of the absence of expression of the protein in neuronal cells. In a second phase, during germ band retraction, the flb function is required specifically in the three pairs of midline glial cells (MG). In the absence of a functional DER protein, these cells die or fail to differentiate correctly, resulting in a fused commissure phenotype.