Genetic engineering of plant volatile terpenoids: effects on a herbivore,a predator and a parasitoid

BACKGROUND: Most insect‐resistant transgenic crops employ toxins to control pests. A novel approach is to enhance the effectiveness of natural enemies by genetic engineering of the biosynthesis of volatile organic compounds (VOCs). Before the commercialisation of such transgenic plants can be pursued, detailed fundamental studies of their effects on herbivores and their natural enemies are necessary. The linalool/nerolidol synthase gene FaNES1 was constitutively expressed from strawberry in three Arabidopsis thaliana accessions, and the behaviour of the aphid Brevicoryne brassicae L., the parasitoid Diaeretiella rapae McIntosh and the predator Episyrphus balteatus de Geer was studied. RESULTS: Transgenic FaNES1‐expressing plants emitted (E)‐nerolidol and larger amounts of (E)‐DMNT and linalool. Brevicoryne brassicae was repelled by the transgenic lines of two of the accessions, whereas its performance was not affected. Diaeretiella rapae preferred aphid‐infested transgenic plants over aphid‐infested wild‐type plants for two of the accessions. In contrast, female E. balteatus predators did not differentiate between aphid‐infested transgenic or wild‐type plants. CONCLUSION: The results indicate that the genetic engineering of plants to modify their emission of VOCs holds considerable promise for facilitating biological control of herbivores. Validation for crop plants is a necessary next step to assess the usefulness of modified volatile emission in integrated pest management. Copyright © 2012 Society of Chemical Industry     

Anaesthetic induction with alfaxalone in the ball python (Python regius): dose response and effect of injection site

Objective

To characterise the minimum dose of intramuscular alfaxalone required to facilitate intubation for mechanical ventilation, and to investigate the impact of cranial versus caudal injection on anaesthetic depth.

Detection of hypoglycin A in the seeds of sycamore (Acer pseudoplatanus) and box elder (A. negundo) in New Zealand; the toxin associated with cases of equine atypical myopathy

CASE HISTORY AND CLINICAL FINDINGS: During April and May 2014 four horses aged between 5 months and 9 years, located in the Canterbury, Marlborough and Southland regions, presented with a variety of clinical signs including recumbency, stiffness, lethargy, dehydration, depression, and myoglobinuria suggestive of acute muscle damage. Two horses were subjected to euthanasia and two recovered. In all cases seeds of sycamore maple (Acer pseudoplatanus) or box elder (A. negundo) were present in the area where the horse had been grazing.

LABORATORY INVESTIGATION: The samaras (seeds) of some Acer spp. may contain hypoglycin A, that has been associated with cases of atypical myopathy in Europe and North America. To determine if hypoglycin A is present in the samaras of Acer spp. in New Zealand, samples were collected from trees throughout the country that were associated with historical and/or current cases of atypical myopathy, and analysed for hypoglycin A. Serum samples from the four cases and four unaffected horses were analysed for the presence of hypoglycin A, profiles of acylcarnitines (the definitive diagnosis for atypical myopathy) and activities of creatine kinase and aspartate aminotransferase.Markedly elevated serum activities of creatine kinase and aspartate aminotransferase, and increased concentrations of selected acylcarnitines were found in the case horses. Hypoglycin A was detected in the serum of those horses but not in the healthy controls. Hypoglycin A was detected in 10/15 samples of samaras from sycamore maple and box elder from throughout New Zealand.

DIAGNOSIS: Cases of atypical myopathy were diagnosed on properties where samaras containing hypoglycin A were also found.

CLINICAL RELEVANCE: Sycamore and box elder trees in New Zealand are a source of hypoglycin A associated with the development of atypical myopathy. If pastured horses present with clinical and biochemical signs of severe muscle damage then the environment should be checked for the presence of these trees. Horses should be prevented from grazing samaras from Acer spp. in the autumn.     

Evaluation of action thresholds for chronic rice insect pests in the Philippines. I. Less frequently occurring pests and overall assessment

Action thresholds as decision tools for insecticide application were developed and tested against the major insect pests of rice at four sites in the Philippines over a 13-year period. Action threshold treatments were compared to the farmers' practice, prophylactic insecticide usage, and an untreated check. Yield loss data using the insecticide check method partitioned yield losses over three crop growth stages in the same test fields. Chronic pests that exceeded action thresholds in 79% of fields were whorl maggot Hydrellia philippina Ferino (Diptera: Ephydridae), defoliators Naranga aenescens Moore and Rivula atimeta (Swinhoe) (Lepidoptera: Noctuidae), leaffolders Cnaphalocrocis medinalis (Guenée) and Marasmia patnalis Bradley (Lepidoptera: Pyralidae), and stemborers Scirpophaga incertulas (Walker) and S. innotata (Walker) (Lepidoptera: Pyralidae). Minor chronic pests reached threshold levels in only one site each: rice bug Leptocorisa oratorius (F.) (Koronadal), whitebacked planthopper Sogatella furcifera (Horvath) (Zaragoza) and green leafhopper Nephotettix virescens (Distant) (Guimba); brown planthopper Nilaparvata lugens (Stål) did not exceed a threshold in any field. Stemborers were the most important pest group in terms of yield loss. Despite the insecticide check method underestimating losses, a mean crop loss of 0.62 t/ha was measured which showed ample scope for corrective action. But loss was evenly distributed across crop growth stages (0.15?–?0.24 t/ha) reducing the impact of insecticides. Action threshold treatments overall outyielded the untreated check, more so in the two sites with highest pest density. The benefit of thresholds was to reduce insecticide usage, as a cost saving. However all the practices showed poor economic returns including the farmers' practice. Farmers' practice employed low insecticide dosages and timing was not consistent with pest damage, but yields were often similar to threshold treatments. Farmers appear to use insecticide more for risk aversion than for profit. The best threshold characters when evaluated against resulting pest density and yield loss criteria showed accuracies >?90% correct decisions. Future work is needed to improve the insecticide response rather than monitoring tools. Thresholds need to be incorporated into improved crop management, which was often found suboptimal by farmers, to take advantage of the high levels of tolerance in modern high tillering cultivars. Crop husbandry practices which improve yield potential such as selection of longer maturing varieties and nitrogen fertilizer may be a more effective pest management strategy than insecticides.     

Mitochondria in Mammalian Sperm Physiology and Pathology: A Review

While, for a long time, the role of mitochondria in sperm physiology and pathology has been largely ignored, recent research points out the mitochondria as a major organelle with key roles in sperm function both under physiological and biotechnological conditions. This paper briefly reviews these novel findings regarding the role of mitochondria in sperm, paying special attention to the most practical, readily applicable, aspects of the topic such as their role as a major source of the sublethal damage that sperm experiments after cryopreservation.     

Erythrocytic pyruvate kinase deficiency and AB blood types in Australian Abyssinian and Somali cats

Objective   To determine the frequency of the mutant pyruvate kinase (PK) allele, haematological parameters and AB blood types of Abyssinian and Somali cats in Australia.
Design   Complete blood cell and reticulocyte counts, DNA PK mutation testing and blood typing were performed in all cats.
Results   A total of 60 cats (36 Abyssinians, 24 Somalis) were included (37 females, 23 males). For the mutant PK allele, three female Somalis were homozygous (affected, 5%), 17 cats were heterozygous (carrier, 28%) and 40 cats tested negative (normal, 67%). Pedigree analysis revealed common ancestry of affected and many carrier cats. Of affected cats, two had regenerative anaemias and all had reticulocytosis (range 64–390 × 10⁹/L; P < 0.001 compared with normal or carrier cats). The only consistent historical sign was lethargy. One affected cat was euthanased 18 months after testing, because of anaemia, neutropenia, anorexia and weight loss. The mutant allele frequency was 0.19 overall (0.29 in Somalis, 0.13 in Abyssinians). All cats had blood type A. The commercial blood typing card method incorrectly identified 12 cats as having type AB blood.
Conclusions    The frequency of the mutant PK allele is high in Australia. Screening for PK deficiency is indicated before mating and in individual cats of these breeds, even in the absence of anaemia and especially when there is reticulocytosis. Although all cats in the present study had blood type A, blood type B is common in these breeds worldwide. Retyping of any AB typed cats by a laboratory technique is recommended.     

Temperature and surface-ocean water balance of the mid-holocene tropical western pacific

Skeletal Sr/Ca and 18O/16O ratios in corals from the Great Barrier Reef, Australia, indicate that the tropical ocean surface approximately 5350 years ago was 1 degrees C warmer and enriched in 18O by 0.5 per mil relative to modern seawater. The results suggest that the temperature increase enhanced the evaporative enrichment of 18O in seawater. Transport of part of the additional atmospheric water vapor to extratropical latitudes may have sustained the 18O/16O anomaly. The reduced glacial-Holocene shift in seawater 18O/16O ratio produced by the mid-Holocene 18O enrichment may help to reconcile the different temperature histories for the last deglaciation given by coral Sr/Ca thermometry and foraminiferal oxygen-isotope records.