A bioavailable strontium (87Sr/86Sr) isoscape for Aotearoa New Zealand: Implications for food forensics and biosecurity.

As people, animals and materials are transported across increasingly large distances in a globalized world, threats to our biosecurity and food security are rising. Aotearoa New Zealand is an island nation with many endemic species, a strong local agricultural industry, and a need to protect these from pest threats, as well as the economy from fraudulent commodities. Mitigation of such threats is much more effective if their origins and pathways for entry are understood. We propose that this may be addressed in Aotearoa using strontium isotope analysis of both pests and products. Bioavailable radiogenic isotopes of strontium are ubiquitous markers of provenance that are increasingly used to trace the origin of animals and plants as well as products, but currently a baseline map across Aotearoa is lacking, preventing use of this technique. Here, we have improved an existing methodology to develop a regional bioavailable strontium isoscape using the best available geospatial datasets for Aotearoa. The isoscape explains 53% of the variation (R2 = 0.53 and RMSE = 0.00098) across the region, for which the primary drivers are the underlying geology, soil pH, and aerosol deposition (dust and sea salt). We tested the potential of this model to determine the origin of cow milk produced across Aotearoa. Predictions for cow milk (n = 33) highlighted all potential origin locations that share similar 87Sr/86Sr values, with the closest predictions averaging 7.05 km away from their true place of origin. These results demonstrate that this bioavailable strontium isoscape is effective for tracing locally produced agricultural products in Aotearoa. Accordingly, it could be used to certify the origin of Aotearoa's products, while also helping to determine if new pest detections were of locally breeding populations or not, or to raise awareness of imported illegal agricultural products.

Highly similar piggyBac elements in Bactrocera that share a common lineage with elements in noctuid moths.

The piggyBac IFP2 transposable element, originally discovered in a Trichoplusia ni cell line, also exists as nearly identical elements in other noctuid lepidopterans, and in several species of the tephritid genus Bactrocera. To further define the distribution of piggyBacs in Bactrocera, and compare their relationship to sequences found in Lepidoptera, a survey by PCR amplification was performed in a range of Bactrocera species. Highly similar piggyBac sequences were found in all B. dorsalis complex species tested, as well as in species in the B. zonata and B. frauenfeldi complexes. All nucleotide sequences had > 94% identity to corresponding sequences in the T. ni IFP2 element, and > 88% identity among the sequences. Conserved primers did not amplify any distantly related sequences that have been found by computational searches in a wider range of insect and non-insect species. Notably, 55 nucleotide substitutions relative to IFP2 were common to all the Bactrocera sequences, 44 of which exist in piggyBacs previously sequenced from moths, with 17 resulting in amino acid substitutions. These piggyBac elements, that apparently traversed orders by horizontal transfer, probably arose from a lineage separate from IFP2 and the other known elements in T. ni. Implications for the presence of nearly identical piggyBacs, in widely distributed insects, to the applied use of piggyBac vectors are discussed.

Cooled Propylene Glycol as a Pragmatic Choice for Preservation of DNA From Remote Field-Collected Diptera for Next-Generation Sequence Analysis.

Next-generation sequencing (NGS)-based methods can now be applied to large population-scale studies, but this demands very high-quality DNA. For specimens collected from remote field locations, DNA degradation can be a problem, requiring logistically challenging preservation techniques. Simpler preservation techniques are therefore required. Prior to collection of exotic fruit fly (Tephritidae) species, a number of readily available preservatives with storage at either 4°C or room temperature were trialed here to determine the DNA quality for three locally available Diptera species, Fannia canicularis (L.), Musca domestica L., and Lucilia sericata Meigen. Considerable variation was observed between the different preservatives, species, and temperatures, but several preservatives at 4°C were favored. Chilled propylene glycol was subsequently used for the storage and carriage of Australian field-collected Bactrocera fruit fly specimens to New Zealand. When processed up to 20 d later, DNA fragments of ∼10-20 kb were obtained for successful genotyping by sequencing analysis. This protocol is therefore recommended as a logistically simple and safe approach for distant collection of dipteran samples for NGS population genomic studies.

Peripartum heart failure: idiopathic cardiomyopathy or compounding cardiovascular events?

During a 12-year period, when more than 106,000 women were delivered, 28 women with peripartum heart failure of obscure etiology that initially was diagnosed as peripartum cardiomyopathy were studied. None had obvious underlying cardiac disease or iatrogenic fluid overload, and in all an assiduous search for underlying cardiovascular disease was launched. In 21 of these 28 women, heart failure was attributed to chronic underlying disease (chronic hypertension in 14, forme fruste mitral stenosis in four, and morbid obesity in one) or viral myocarditis. Importantly, these women also had multiple compounding cardiovascular factors--preeclampsia, cesarean section, anemia, and infection--which, when superimposed on those of pregnancy, acted in concert to cause heart failure. In seven women, the cause for cardiomegaly and global hypokinesis was not found, and peripartum cardiomyopathy was diagnosed. Compared with women with explicable causes of peripartum heart failure, these women did poorly: six had persistent cardiomegaly and heart failure, and four of these died within four months to eight years. From these observations, the authors conclude that idiopathic peripartum cardiomyopathy is uncommon, and that in most women with peripartum heart failure of obscure etiology, underlying chronic disease will be identified. Heart failure in these women ensues when the cardiovascular demands of normal pregnancy are amplified further by common pregnancy complications superimposed upon these underlying conditions that cause compensated ventricular hypertrophy.

Rapid and accurate typing of Dichelobacter nodosus using PCR amplification and reverse dot-blot hybridisation.

Here we describe an approach to genotyping D. nodosus, based on variation in the fimbrial subunit gene (fimA), which uses polymerase chain reaction (PCR) amplification and hybridisation to immobilised oligonucleotides (PCR/oligotyping). The variable region of D. nodosus fimA, amplified and labelled with digoxigenin (DIG) in a single multiplex PCR amplification, was hybridised to a panel of group- and type-specific poly-dT tailed oligonucleotides that were immobilised on a nylon membrane strip. A mixture of positive control poly-dT tailed oligonucleotides was also included on the membrane. After hybridisation the membrane was washed to a defined specificity, and DIG-labelled fragments hybridising were detected with nitroblue tetrazolium (NBT) and 5-bromo-4-chloro-3-indolyl phosphate (SCIP). The specificity of the oligonucleotides was verified by the lack of cross-reactivity with D. nodosus fimA sequences that had a single base difference. DNA from 14 footrot samples previously genotyped by PCR-SSCP/sequencing [Vet. Microbiol. 71 (2000) 113], was assayed using the PCR/oligotyping technique. All types of D. nodosus which had been detected previously with a PCR-SSCP/sequencing method were detected by this procedure. However, for three of the 14 footrot samples, PCR/oligotyping detected additional types of D. nodosus. Further PCR amplification using type-specific primers, confirmed that these types of the bacterium were present in the footrot samples. These results indicate that PCR/oligotyping is a specific, accurate, and useful tool for typing footrot samples. In combination with a rapid DNA extraction protocol, D. nodosus strains present in a footrot sample can be accurately identified in less than 2 days.

DNA barcodes for biosecurity: invasive species identification.

Biosecurity encompasses protecting against any risk through 'biological harm', not least being the economic impact from the spread of pest insects. Molecular diagnostic tools provide valuable support for the rapid and accurate identification of morphologically indistinct alien species. However, these tools currently lack standardization. They are not conducive to adaptation by multiple sectors or countries, or to coping with changing pest priorities. The data presented here identifies DNA barcodes as a very promising opportunity to address this. DNA of tussock moth and fruit fly specimens intercepted at the New Zealand border over the last decade were reanalysed using the cox1 sequence barcode approach. Species identifications were compared with the historical dataset obtained by PCR-RFLP of nuclear rDNA. There was 90 and 96% agreement between the methods for these species, respectively. Improvements included previous tussock moth 'unknowns' being placed to family, genera or species and further resolution within fruit fly species complexes. The analyses highlight several advantages of DNA barcodes, especially their adaptability and predictive value. This approach is a realistic platform on which to build a much more flexible system, with the potential to be adopted globally for the rapid and accurate identification of invasive alien species.

Genetic relationships in Lens species and parentage determination of their interspecific hybrids using RAPD markers.

Broadening of the genetic base and systematic exploitation of heterosis in cultivated lentils requires reliable information on genetic diversity in the germplasm. The ability of random amplified polymorphic DNA (RAPD) to distinguish among different taxa of Lens was evaluated for several geographically dispersed accessions/cultivars of four diploid Lens species. This study was carried out to assess whether RAPD data can provide additional evidence about the origin of the cultivated lentil and to measure genetic variability in lentil germplasm. Three cultivars of Lens culinaris ssp. culinaris, including one microsperma, and two macrosperma types, and four wild species (L. culinaris ssp. orientalis, L. odemensis and L. nigricans) were evaluated for genetic variability using a set of 1 11-mer and 14 random 10-mer primers. One hundred and fifty-eight reproducible and scorable DNA bands were observed from these primers. Genetic distances between each of the accessions were calculated from simple matching coefficients. Split decomposition analysis of the RAPD data allowed construction of an unrooted tree. This study revealed that (1) the level of intraspecific genetic variation in cultivated lentils is narrower than that in some wild species. (2) L. culinaris ssp. orientalis is the most likely candidate as a progenitor of the cultivated species, (3) L. nigricans accession W6 3222 (unknown) and L. c. ssp. orientalis W6 3244 (Turkey) can be reclassified as species of L. odemensis and (4) transmission of genetic material in Lens interspecific hybrids is genotypically specific, as identified by the RAPD markers in our study.