Highly parallel oligonucleotide purification and functionalization using reversible chemistry

We have developed a cost-effective, highly parallel method for purification and functionalization of 5′-labeled oligonucleotides. The approach is based on 5′-hexa-His phase tag purification, followed by exchange of the hexa-His tag for a functional group using reversible reaction chemistry. These methods are suitable for large-scale (micromole to millimole) production of oligonucleotides and are amenable to highly parallel processing of many oligonucleotides individually or in high complexity pools. Examples of the preparation of 5′-biotin, 95-mer, oligonucleotide pools of >40K complexity at micromole scale are shown. These pools are prepared in up to ~16% yield and 90–99% purity. Approaches for using this method in other applications are also discussed

Transcriptomic evidence that von Economo neurons are regionally specialized extratelencephalic-projecting excitatory neurons.

von Economo neurons (VENs) are bipolar, spindle-shaped neurons restricted to layer 5 of human frontoinsula and anterior cingulate cortex that appear to be selectively vulnerable to neuropsychiatric and neurodegenerative diseases, although little is known about other VEN cellular phenotypes. Single nucleus RNA-sequencing of frontoinsula layer 5 identifies a transcriptomically-defined cell cluster that contained VENs, but also fork cells and a subset of pyramidal neurons. Cross-species alignment of this cell cluster with a well-annotated mouse classification shows strong homology to extratelencephalic (ET) excitatory neurons that project to subcerebral targets. This cluster also shows strong homology to a putative ET cluster in human temporal cortex, but with a strikingly specific regional signature. Together these results suggest that VENs are a regionally distinctive type of ET neuron. Additionally, we describe the first patch clamp recordings of VENs from neurosurgically-resected tissue that show distinctive intrinsic membrane properties relative to neighboring pyramidal neurons

Characterization of miRNAs in Response to Short-Term Waterlogging in Three Inbred Lines of Zea mays

Waterlogging of plants leads to low oxygen levels (hypoxia) in the roots and causes a metabolic switch from aerobic respiration to anaerobic fermentation that results in rapid changes in gene transcription and protein synthesis. Our research seeks to characterize the microRNA-mediated gene regulatory networks associated with short-term waterlogging. MicroRNAs (miRNAs) are small non-coding RNAs that regulate many genes involved in growth, development and various biotic and abiotic stress responses. To characterize the involvement of miRNAs and their targets in response to short-term hypoxia conditions, a quantitative real time PCR (qRT-PCR) assay was used to quantify the expression of the 24 candidate mature miRNA signatures (22 known and 2 novel mature miRNAs, representing 66 miRNA loci) and their 92 predicted targets in three inbred Zea mays lines (waterlogging tolerant Hz32, mid-tolerant B73, and sensitive Mo17). Based on our studies, miR159, miR164, miR167, miR393, miR408 and miR528, which are mainly involved in root development and stress responses, were found to be key regulators in the post-transcriptional regulatory mechanisms under short-term waterlogging conditions in three inbred lines. Further, computational approaches were used to predict the stress and development related cis-regulatory elements on the promoters of these miRNAs; and a probable miRNA-mediated gene regulatory network in response to short-term waterlogging stress was constructed. The differential expression patterns of miRNAs and their targets in these three inbred lines suggest that the miRNAs are active participants in the signal transduction at the early stage of hypoxia conditions via a gene regulatory network; and crosstalk occurs between different biochemical pathways

Near-infrared luminescence of Yb3+, Nd3+, and Er3+ azatriphenylene complexes

Near-infrared luminescent ytterbium(III), neodymium(III), and erbium(III) complexes containing novel organic chromophores derived from azatriphenylene have been prepared and spectroscopically studied. The complexes can be excited from 350 to 450 nm, leading after intramolecular energy transfer to intense lanthanide luminescence in acetonitrile. Quenching of the luminescence of the complexes by molecular oxygen reveals information on the rate of energy transfer from the “antenna” to the lanthanide ion

Synthesis of neutral, water-soluble calix[4]arenes

Novel neutral water-soluble calix[4]arenes were synthesized via chlorosulfonylation of lower rim functionalized calix[4]arenes followed by reaction with hydroxyl group containing amines. The solubility of these calix[4]arenes sulfonamides in water varies from ∼ 10-5 to 3.1⋅10-1 M. A route via hydrophobically protected amines improves the purification

Diazatriphenylene complexes of Eu3+ and Tb3+; promising light-converting systems with high luminescence quantum yields

Diazatriphenylene (1) displays the unique property that it sensitizes the long lived luminescence of both Tb3+ and Eu3+ with high efficiency (quantum yields of 0.55 and 0.41, respectively) while allowing near UV excitation ( <340 nm), which makes the lanthanide complexes of 1 very suitable for time-resolved multi-probe detection

Diazatriphenylene complexes of Eu3+ and Tb3+; promising light-converting systems with high luminescence quantum yields

Diazatriphenylene (1) displays the unique property that it sensitizes the long lived luminescence of both Tb3+ and Eu3+ with high efficiency (quantum yields of 0.55 and 0.41, respectively) while allowing near UV excitation ( &lt;340 nm), which makes the lanthanide complexes of 1 very suitable for time-resolved multi-probe detection