Characterisation and quantification of equine interferon gamma

Interferon-gamma (IFN-gamma) is a key cytokine in cell-mediated immunity. To measure IFN-gamma production of equine lymphocytes (eqIFN-gamma), we developed a quantitative ELISA. Monoclonal antibodies (mAb) were produced against bacterially derived eqIFN-gamma. The mAbs recognised recombinant and lymphocyte-derived eqIFN-gamma in ELISA, Western blotting, as well as flow cytometric and microscopic analysis. In contrast to bacterially derived material, mammalian and insect cell-derived eqIFN-gamma was biologically active but could be neutralised by one of the monoclonal antibodies. Unexpectedly, glycosylation seemed to be required for antiviral activity of eqIFN-gamma.     

Comparative evaluation of live marker vaccine candidates "CP7_E2alf" and "flc11" along with C-strain "Riems" after oral vaccination

Due to the tremendous socio-economic impact of classical swine fever (CSF) outbreaks, emergency vaccination scenarios are continuously under discussion. Unfortunately, all currently available vaccines show restrictions either in terms of marker capacities or immunogenicity. Recent research efforts were therefore directed at the design of new modified live marker vaccines. Among the most promising candidates the chimeric pestiviruses "CP7_E2alf" and "flc11" were identified. Within an international research project, these candidates were comparatively tested in challenge experiments after a single oral vaccination. Challenge infection was carried out with highly virulent CSF virus strain "Koslov", 14 or 21 days post vaccination (dpv), respectively. Safety, efficacy, and marker potential were addressed. All assessments were done in comparison with the conventional "gold standard" C-strain "Riems" vaccine. In addition to the challenge trials, multiple vaccinations with both candidates were performed to further assess their marker vaccine potential. All vaccines were safe and yielded full protection upon challenge 21 days post vaccination. Neither serological nor virological investigations showed major differences among the three vaccines. Whereas CP7_E2alf also provided clinical protection upon challenge at 14 days post vaccination, only 50% of animals vaccinated with flc11, and 83% vaccinated with C-strain "Riems" survived challenge at this time point. No marked differences were seen in protected animals. Despite the fact that all multiple-vaccinated animals stayed sero-negative in the accompanying marker test, the discriminatory assay remains a weak point due to delayed or inexistent detection of some of the vaccinated and subsequently infected animals. Nevertheless, the potential as live marker vaccines could be confirmed for both vaccine candidates. Future efforts will therefore be directed at the licensing of "Cp7_E2alf" as the first live marker vaccine for CSF.     

Agronomic performance of winter wheat grown under highly divergent soil moisture conditions in rainfed and water‐managed environments

Even in the temperate climates of Europe, increasing early season drought and rising air temperature are presenting new challenges to farmers and wheat breeders. Sixteen winter wheat (Triticum aestivum L.) genotypes consisting of three hybrids, six line cultivars and two breeding lines from Germany as well as five line cultivars from France, Austria, Slovakia, Hungary and the Ukraine (referred to as “exotic” lines) have been included in this study. The genetic materials were evaluated over three growing seasons under a range of soil moisture regimes at the three North German sites Braunschweig (irrigated and drought‐stressed), Warmse (rainfed) and Söllingen (rainfed). The average grain yields in the twelve growth environments (water regime × season combinations) ranged from 6.1 to 13.5 t ha^?1. The exotic lines showed little evidence of specific phenological adaptation to drought although they are frequently faced with water scarcity in their countries of origin. The hybrids and German lines exhibited higher regression coefficients (b_i) to environmental means than the exotic lines, indicating particular adaptation to favourable growing conditions. The phenotypical correlations of grain yield between the various environments were high, ranging for instance from 0.6 to 0.8 for the irrigated and drought‐stressed environments at Braunschweig. It is thus expected that in the foreseeable future continued selection aiming at high yield potential will suffice as a means to counter the expected increase in droughts.     

Early pregnancy alters the metabolic responses to restricted nutrition in sheep

This study investigated whether a 27-day period of nutrition at half-maintenance during early pregnancy (up to Day 14) could alter maternal endocrine responses. Forty-six ewes were fed all or half of their maintenance requirements and slaughtered on Day 14 of the oestrous cycle or pregnancy. We used real time RT-PCR to study gene expression of growth hormone receptor (GHR) and leptin in adipose tissue and GHR, GHR1A and of the insulin-like growth factor I (IGF-I) in the liver. Blood profiles of metabolites and metabolic hormones were also determined. Throughout the experiment, underfed animals presented lower body weight and body condition, greater plasma concentrations of non-esterified fatty acids (NEFA), and lower plasma concentrations of leptin, compared to adequately fed animals. Undernutrition affected the patterns of gene expression in adipose and hepatic tissues, and the responses differed between pregnant and non-pregnant ewes. In adequately fed ewes, pregnancy up-regulated leptin mRNA expression in adipose tissue, a response that was impaired in underfed ewes. The hepatic expression of IGF-I mRNA was increased by pregnancy in underfed animals while no effect was observed in adequately fed ewes. It remains to be determined whether the changes in the endocrine milieu are paralleled by modifications in uterine gene expression that could alter the environment of the embryo during early pregnancy.     

Sperm quality in male <Emphasis Type="Italic">Barbus barbus</Emphasis> L. fed different diets during the spawning season

Sperm quality of Barbus barbus L. was compared among the three following dietary regimes: Group A, fed 100% commercial diet (Karpico™ containing 33% crude protein and 6% fat), Group B, fed 78% commercial diet and 22% frozen chironomid (Chironomus plumosus) larvae, and Group C, fed 56% commercial diet and 44% frozen chironomid larvae. Concentrations of polyunsaturated fatty acids (PUFAs) in Group A, B, and C were 39.1, 42.0, and 44.6, respectively, as a percentage of total fatty acids. Sperm morphology, volume, concentration and motility, total number of spermatozoa, and osmolality of the seminal plasma were compared during the spawning season. Dietary regime did not influence sperm volume, concentration, or total number of spermatozoa, osmolality of seminal plasma, or the percentage of motile sperm, but significantly affected sperm morphology (except for anterior and posterior parts of the midpiece) and sperm velocity (P < 0.05). Groups B and C showed similar sperm characteristics during the spawning season compared to Group A. Almost all parameters changed either among or within groups during the spawning season, suggesting differences in terms of the optimal time for sperm collection. The best time for sperm collection was March for Group A, but April for Groups B and C, when the osmolality of the seminal plasma measured 289 mOsmol kg⁻¹ and sperm motility was maximal. Spermatogenesis, hydration, and cell decomposition were confirmed as the three major parameters controlling sperm characteristics during the spawning season. The possible correlation between sperm morphology and motility requires further study.