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Biology subjects

Parker, B. M.

Publications and source records attributed to Parker, B. M..

2 recordsLinked to original sources

CRISPR-based diagnostics detects invasive insect pests

Rapid identification of organisms is essential across many biological and medical disciplines, from understanding basic ecosystem processes and how organisms respond to environmental change, to disease diagnosis and detection of invasive pests. CRISPR-based diagnostics offers a novel and rapid alternative to other identification methods and can revolutionize our ability to detect organisms with high accuracy. Here we describe a CRISPR-based diagnostic developed with the universal cytochrome-oxidase 1 gene (CO1). The CO1 gene is the most sequenced gene among Animalia, and therefore our approach can be adopted to detect nearly any animal. We tested the approach on three difficult-to-identify moth species (Keiferia lycopersicella, Phthorimaea absoluta, and Scrobipalpa atriplicella) that are major invasive pests globally. We designed an assay that combines recombinase polymerase amplification (RPA) with CRISPR for signal generation. Our approach has a much higher sensitivity than other real time-PCR assays and achieved 100% accuracy for identification of all three species, with a detection limit of up to 120 fM for P. absoluta and 400 fM for the other two species. Our approach does not require a lab setting, reduces the risk of cross-contamination, and can be completed in less than one hour. This work serves as a proof of concept that has the potential to revolutionize animal detection and monitoring.

genetics↗

Recombinant expression and characterisation of a lipase from the Antarctic zooplankton Salpa thompsoni

Cold marine environments are abundant on earth and represent a rich resource for low temperature enzymes. Here we apply in silico bioprospecting methods followed by in vitro expression and biochemical analyses to characterise a novel low temperature lipase from the Antarctic tunicate Salpa thompsoni. A 586 amino acid pancreatic lipase-like gene was identified from S. thompsoni transcriptomic data, expressed as a hexahistadine fusion protein in Escherichia coli at 10{degrees}C and purified by affinity chromatography. Hydrolysis of the synthetic substrate {rho}-nitrophenyl butyrate (PNPB) showed that this recombinant protein has optimal activity at 20 {degrees}C and pH 7, and a specific activity of 3.16 U/mg under this condition. Over 60% of enzyme activity was maintained between 15 to 25 {degrees}C, with a sharp decrease outside this range. These results are indicative of cold active psychrophilic enzyme activity. A meta-analysis of lipase activities towards PNPB showed that the novel S. thompsoni lipase displays a higher activity at lower temperatures relative to previously characterised enzymes. The work demonstrates a methodology for conversion of transcriptomic to in vitro expression data for the discovery of new cold-active biocatalysts from marine organisms.

synthetic biology↗