Australia's Response to COVID-19.

Australia suffered two waves of the coronavirus disease 2019 pandemic in 2020: the first lasting from February to July 2020 was mainly caused by transmission from international arrivals, the second lasting from July to November was caused by breaches of hotel quarantine which allowed spreading into the community. From a second wave peak in early August of over 700 new cases a day, by November 2020 Australia had effectively eliminated community transmission. Effective elimination was largely maintained in the first half of 2021 using snap lockdowns, while a slow vaccination programme left Australia lagging behind comparable countries.

Expression of the Isochrysis C18-delta9 polyunsaturated fatty acid specific elongase component alters Arabidopsis glycerolipid profiles.

A cDNA isolated from the prymnesiophyte micro-alga Isochrysis galbana, designated IgASE1, encodes a fatty acid elongating component that is specific for linoleic acid (C18:2n-6) and alpha-linolenic acid (C18:3n-3). Constitutive expression of IgASE1 in Arabidopsis resulted in the accumulation of eicosadienoic acid (EDA; C20:2n-6) and eicosatrienoic acid (ETrA; C20:3n-3) in all tissues examined, with no visible effects on plant morphology. Positional analysis of the various lipid classes indicated that these novel fatty acids were largely excluded from the sn-2 position of chloroplast galactolipids and seed triacylglycerol, whereas they were enriched in the same position in phosphatidylcholine.

Production of very long chain polyunsaturated omega-3 and omega-6 fatty acids in plants.

We report the production of two very long chain polyunsaturated fatty acids, arachidonic acid (AA) and eicosapentaenoic acid (EPA), in substantial quantities in a higher plant. This was achieved using genes encoding enzymes participating in the omega3/6 Delta8 -desaturation biosynthetic pathways for the formation of C20 polyunsaturated fatty acids. Arabidopsis thaliana was transformed sequentially with genes encoding a Delta9 -specific elongating activity from Isochrysis galbana, a Delta8 -desaturase from Euglena gracilis and a Delta5 -desaturase from Mortierella alpina.

The variant 'his-box' of the C18-Delta9-PUFA-specific elongase IgASE1 from Isochrysis galbana is essential for optimum enzyme activity.

IgASE1, a C18-Delta9-polyunsaturated fatty acid-specific fatty acid elongase component from Isochrysis galbana, contains a variant histidine box (his-box) with glutamine replacing the first histidine of the conserved histidine-rich motif present in all other known equivalent proteins. The importance of glutamine and other variant amino acid residues in the his-box of IgASE1 was determined by site-directed mutagenesis. Results showed that all the variation in amino acid sequence between this motif in IgASE1 and the consensus sequences of other elongase components was required for optimum enzyme activity.

Isolation and characterization of a cDNA encoding a Delta8 sphingolipid desaturase from Aquilegia vulgaris.

We have isolated a cDNA encoding the Delta(8) sphingolipid desaturase from the plant Aquilegia vulgaris L. via a PCR-based strategy using primers designed to target the conserved histidine box regions of microsomal desaturases. The function of the cDNA was confirmed by expression in the yeast, Saccharomyces cerevisiae.