Biofortification of tomato (Solanum lycopersicum) fruit with the anticancer compound methylselenocysteine using a selenocysteine methyltransferase from a selenium hyperaccumulator

Methylselenocysteine (MeSeCys) is an amino acid derivative that possesses potent anticancer activity in animals. Plants that can tolerate growth on soils with high Se content, known as Se hyperaccumulators, do so by converting inorganic Se to MeSeCys by the enzyme selenocysteine methyltransferase (SMT). A cDNA encoding the SMT from a Se hyperaccumulator was overexpressed in tomato (Solanum lycopersicum). Transgenic plants were provided with selenite or selenate to the roots during fruit development, and liquid chromatography-mass spectrometry was used to show that MeSeCys accumulated in the fruit but not in the leaves. Depending on the transgenic line and Se treatment, up to 16% of the total Se in the fruit was present as MeSeCys. MeSeCys was produced more effectively from selenite on a percentage conversion basis, but greater accumulation of MeSeCys could be achieved from selenate due to its better translocation from the roots. MeSeCys was heat stable and survived processing of the fruit to tomato juice.     

Evaluation of methods of rapid mass killing of segregated early weaned piglets

The operational logistics of mass killing of healthy, surplus piglets by manual blunt force trauma, controlled blunt force trauma, intraperitoneal injection of barbiturate, and free bullet were recorded. Objective performance variables evaluated were, speed of application, human resource and input cost, animal restraint required, and failure rate. Subjective evaluation of esthetics and difficulty of application indicated manual blunt force trauma is an unacceptable technique. Under field conditions, physical methods of killing were superior to intraperitoneal injection of concentrated pentobarbital. Considering animal welfare metrics in isolation, controlled blunt force trauma was superior to all other techniques attempted.     

Lack of evidence for an association between MHC diversity and the development of bovine neonatal pancytopenia in Holstein dairy cattle

Bovine neonatal pancytopenia (BNP), a disease of neonatal calves, has been described in a number of European countries since 2006. The disease results in high mortality of calves aged 1-4 weeks and is characterised by severe bone marrow pathology resulting in profound thrombocytopenia and consequent haemorrhagic diathesis. A number of hypotheses including a novel virus infection, plant toxins, a vaccine associated isoimmune disease, or a genetic defect have been suggested to explain the aetiology of this disease. However, as the number of cases in affected herds remains small, it is hypothesised that the genetic background of the calf may influence disease susceptibility. To test this we focused on the class II region of the major histocompatibility complex (MHC) which is often associated with variations in immune response and susceptibility to antibody mediated autoimmune disease. Forty-three cases of BNP and sixty-eight controls were genotyped at the polymorphic class II MHC-DRB3 locus. Twenty DRB3 alleles were identified with seven appearing at frequencies ≥ 0.05. A comparison of the allelic frequencies between diseased and control groups showed that there was no evidence for any significant differences, suggesting that the MHC does not appear to be a predisposing risk factor in the development of BNP in Holstein dairy cattle.     

Inter- and Intra-specific Differences in the Response of Chinese Leafy Vegetables to Ozone

The response to ozone (O₃) of a range of Chinese leafy vegetables was investigated with respect to both inter- and intra-specific differences in sensitivity. In the interspecific experiment local Chinese cultivars of pak choi, rape, leaf mustard, leaf lettuce and coriander were fumigated with 90?ppb O₃ for 9?h daily for 22?C30?days. A similar fumigation was carried out using four different cultivars of pak choi. Sequential measurements were made of leaf injury, photosynthetic rate, stomatal conductance and chlorophyll fluorescence, together with dry weights at a final harvest. O₃ injury appeared as white or yellow blemishes on the leaf surface of all species. The first signs of injury were seen following only 3-days?? O₃ exposure (pak choi); the extent of injured leaf area increased over time for all species and cultivars, with 44.6% of the leaf area visibly injured for leaf mustard, the species with the greatest extent of injury, following 30-days?? exposure. Significant reductions in photosynthetic rate (22.7?C40.7%) and stomatal conductance (19.1?C33.1%) were found for all species and cultivars following O₃ exposure. Plant productivity was also reduced in O₃ compared to filtered air, with significant yield reductions for all species (11.1?C50.8% above-ground dry weight) as well as for all cultivars of pak choi (15.8?C28.1% above-ground dry weight). The mechanisms for observed impacts are discussed, together with the implications for current and future production of vegetables in the southern China province of Guangdong.     

Dominant sources of dietary carbon and nitrogen for shrimp reared in extensive rice-shrimp ponds

Stable isotope analysis was used to determine the sources of dietary nitrogen (N) and carbon (C) for shrimp during the rearing phase in extensive rice‐shrimp ponds in My Xuyen and Gia Rai districts, Vietnam. Farm‐made feed was added as a food source in shrimp ponds in My Xuyen district, and based on stable isotope analyses, was generally a poor dietary source. The commercial formulated feed used in Gia Rai also appeared to contribute little directly to the nutritional needs of the shrimp. In contrast, the natural biota in all ponds appeared to contribute substantially. In particular, biota from beam trawls and benthic organic matter were the most likely sources of nutrition in My Xuyen ponds, while benthic organic matter was the main source in Gia Rai ponds. δ¹⁵N ratios in the natural biota in My Xuyen farms decreased over the growing season, suggesting increased N fixation in the case of the benthic organic matter reaching values as low as 1‰. This suggests N‐limitation in the ponds and that natural biota become increasingly dependent on N fixed by algae and/or other microorganisms. There is the potential to promote the growth of the plankton and hence, the other natural biota, by the judicious addition of fertilizer.     

Base-catalysed hydrolysis of (E)- and (Z)-mevinphos

The rates at which (E)- and (Z)-mevinphos are hydrolysed in aqueous solutions in the pH range 8.7–11.5, and in the temperature range 30–50°C, have been measured. The overall activation parameters have been calculated, and equations to allow calculation of the rates in any basic conditions are given. The complicated routes by which (E)- and (Z)-mevinphos are hydrolysed to simple molecules have been deduced. The rates for the individual steps in each route have been either measured experimentally, or have been calculated through analogue simulation of all the reactions, by matching the calculated to the observed ultraviolet spectral changes during hydrolysis. It is proposed that (Z)-2-carboxyl-1-methylvinyl dimethyl phosphate is not observed as a hydrolysis product of (Z)-mevinphos because it decomposes by an extremely fast intramolecular reaction. The reasons for the greater lability of (E)-mevinphos are also discussed.