Ability to share emotions of others as a foundation of social learning.

The natural habitats of most species are far from static, forcing animals to adapt to continuously changing conditions. Perhaps the most efficient strategy addressing this challenge consists of obtaining and acting upon pertinent information from others through social learning. We discuss how animals transfer information via social channels and what are the benefits of such exchanges, playing out on different levels, from theperception of socially delivered information to emotional sharing, manifesting themselves across different taxa of increasing biological complexity. We also discuss how social learning is influenced by different factors including pertinence of information for survival, the complexity of the environment, sex, genetic relatedness, and most notably, the relationship between interacting partners. The results appear to form a consistent picture once we shift our focus from emotional contagion as a prerequisite for empathy onto the role of shared emotions in providing vital information about the environment. From this point of view, we can propose approaches that are the most promising for further investigation of complex social phenomena, including learning from others.

Formation of fumonisins and other secondary metabolites by Fusarium oxysporum and F. proliferatum: a comparative study.

The principal aim of this study was to estimate the formation of fumonisins (FB(1) and FB(2)), moniliformin (MON), and ergosterol (ERG) by Fusarium oxysporum and Fusarium proliferatum, while the formation of beauvericin (BEA) was estimated by the latter Fusarium species only. Moreover, the effect of temperature on the biosynthesis of mycotoxins was also evaluated. Fumonisins were formed by F. proliferatum, with the highest yield at 18 degrees C (720.0-1976.6 microg g(-1) for FB(1), 74.2-670.8 microg g(-1) for FB(2)) and only by three of four F. oxysporum strains at a very low level (0.02-4.77 microg g(-1) for FB(1), 0.02-2.15 microg g(-1) for FB(2)). The amount of MON formed by F. proliferatum was the highest (p < 0.001) at 32 degrees C (3056.87 microg g(-1)), while MON biosynthesis by F. oxysporum was lower 227.54 microg g(-1) (p < 0.001). BEA was produced by F. proliferatum with the highest level at 25 degrees C (p < 0.001). ERG-recognized as an indicator of fungal biomass development and as a consequence of mycotoxin formation-was found at the highest concentration at a biosynthesis temperature of 25 degrees C for F. proliferatum and F. oxysporum (p < 0.001).

Reaction of winter wheat (Triticum aestivum L.) cultivars to infection with Fusarium spp.: mycotoxin contamination in grain and chaff.

This study compares the susceptibility of winter wheat (Triticum aestivum L.) cultivars to Fusarium head blight (FHB) and accumulation of mycotoxins in kernels and chaff under different climatic conditions in two locations-Cerekwica near Poznan (Central West Poland) and Sitaniec, near Zamosc, Lublin region (South East Poland). Very high variations were found in the concentrations of mycotoxins (zearalenone, ZEA; nivalenol, NIV; deoxynivalenol, DON; moniliformin, MON) in examined fractions: Fusarium-damaged kernels (FDK) and healthy looking kernels (HLK) and in chaff for individual cultivars in both locations. In most cases, significantly higher concentrations of investigated toxins were recorded in wheat from the area of Lublin than from Poznan (p < 0.05). The highest Fusarium infection rates and mycotoxin biosynthesis levels were observed in the Lublin location, with the percentage of the FDK fraction ranging 8.1-81.6. In this region, ZEA concentration (microg g(-1)) after inoculation with F. culmorum and F. graminearum ranged from 0.02-0.48 and 0.32-1.04, respectively. In the Poznan area, the toxin concentrations were considerably lower, ranging 0.01-0.10 and 0.03-0.13 microg g(-1) for both isolates, respectively. The concentration of DON was significantly higher than ZEA or NIV levels. The levels of MON accumulation (microg g(-1)) in the FDK fraction were between 0.14 and 1.73 (Poznan area) and ND (not detected) to 2.51 (Lublin area). F. avenaceum infection rate ranged 7-35% in samples where the toxin was detected.

Accumulation of mycotoxins in forage of winter pasture during prolonged utilisation of sward.

The concentration of mycotoxins in sward depending on time of pre-utilisation in summer and date of harvest in winter was analysed during the 2000-2002 vegetation seasons. Additionally, the yield of pasture sward was estimated. Higher concentrations of ochratoxin A--respectively: 0.55 and 050 ng/g DM--were found in the pasture sward harvested in December and January when compared to the sward collected in November (0.36 ng/g DM). The average concentration of zearalenone varied from 2.74 ng/g DM in December, to 6.00 ng/g DM in November and 9.77 ng/g DM in January. The highest concentration of ochratoxin A was 1.82 ng/g DM and zearalenone 47.89 ng/g DM. The highest number of samples in which ochratoxin A exceeded the level of 0.3 ng/g DM was noted in sward harvested in January (61.1%), while in the case of zearalenone, the number of samples containing this mycotoxin at a level exceeding 3.0 ng/g DM varied from 55.6% in December to 66.7% in November and January. It seems that the percentage of ochratoxin A positive samples and the toxin concentration level in the sward of winter pastures increased during the time of sward regrowth.

Moniliformin accumulation in kernels of oats used for food and feed purposes.

Inoculation experiments with 12 genotypes of oats (9 lines: CHD 894, CHD 1095, CHD 1296, CHD 1607, CHD 1653, CHD 1692, STH 2293, STH 2393, STH 2494, STH 2694 and 2 cultivars: Farys, Slawko) were performed during the vegetation seasons of 1999 - 2000 in Zamosc region in the South - Eastern part of Poland.Panicles of oats were inoculated with a conidial suspension ofFusarium avenaceum, which caused the following average reductions of traits: yield by 37.8 % and weight of 1000 kernels by 40.2 % respectively.The highest susceptibility to scab development caused by theF. avenaceum inoculation was found particularly for two lines (CHD 894, and CHD 1296) while cultivar Farys and line CHD 1607 exhibited the highest resistance to the disease in terms of TKW and yield reductions after inoculation. During 2 consecutive years (1999 and 2000 respectively) the average level of moniliformin accumulation (mg/kg) in positive samples was respectively 0.51 and 0.12 the highest being 1.11 and 0.26, while the lowest was 0.30 and 0.01.

Fusariotoxins in kernels of winter wheat cultivars field samples collected during 1993 in Poland.

In South-Eastern region of Poland (near Lublin), where frequency of scab (fusariosis) is much higher than in other parts of the country, during harvest of 1993 kernels of 25 winter wheat cultivars were collected. On the basis of morphological studies Fusarium graminearum was found in 42% of investigated samples while other fungi appeared less frequently: F. nivale and F. poae (35%), F. avenaceum (31%) and F. culmorum (12%). Chemical analysis (by HPLC) revealed that the tested cultivars were contaminated with deoxynivalenol (96% of investigated samples), its acetyl derivatives (48%), nivalenol (76%) and moniliformin (28%). The average levels of the metabolite concentrations were as follows: 104; 16; 97; and 63 micrograms/kg, respectively. Co-occurrence of 2 toxic metabolites was found in the following percentage of the positive samples: deoxynivalenol and nivalenol (72%), deoxynivalenol and moniliformin, as well as nivalenol and moniliformin (24%). Usually (71-83% of contaminated samples) mycotoxins were accumulated in the concentration range > or = 10, < 100 micrograms/kg.

Genetic determination of variability of barley doubled haploids inoculated with Fusarium culmorum (W.G.Sm.) Sacc. with regard to mycotoxin accumulation and reduction in yield traits.

The genetic determination of variability of barley doubled haploid (DH) lines in regard of their susceptibility to Fusarium head blight caused by Fusarium culmorum was studied. The susceptibility was evaluated in 3-year field experiment on the basis of reduction in yield traits and myotoxin accumulation in infected kernels. The following traits were analysed in inoculated and control plants: kernel number and weight per ear, 1000-kernel weight, percentage of plump kernels (>2.5 mm), deoxynivalenol (DON) content and nivalenol (NIV) content of kernels. On the basis of the obtained data, heritability coefficient (ratio of genotypic to phenotypic variance) was assessed, and genetic parameters as well as the number of effective factors were estimated. Heritability coefficients calculated from two-way analysis of variance, i.e.regarding the influence of years and year x genotype interaction, appeared to be exceptionally low and ranged from 5.2% for the reduction in plump kernels to 38.2% for the reduction in 1000-kernel weight. In the case of mycotoxin accumulation about 60% of the observed variability in NIV concentrations and 30% in DON concentration resulted form genetic differences among lines. Additive effects of genes were important for all the analysed traits. Significant effects of dominance and dominance x dominance were observed for 1000-kernel weight and percentage of plump kernels. Moreover, it was found that the observed variability in yield trait reduction resulted from segregation of 5-6 effective factors, DON contents from 4 factors, while NIV content from 5 factors.

Deoxynivalenol accumulation and other scab symptoms in six romanian wheat genotypes inoculated withFusarium graminearum.

At anthesis, under field conditions at Fundulea, each of 6 Romanian winter wheat genotypes was inoculated with 3Fusarium graminearum isolates used individually.Fusarium head blight (FHB) was assessed according to the following traits: relative weight of spikes (RWS), percentage of Fusarium damaged kernels (FDK), relative weight of kernels per head (RWKH), area under the disease progress curve (AUDPC) and deoxynivalenol (DON) content in total sample of kernels. Correlations between these traits and parameters revealed important differences between examined wheat genotypes in: DON accumulation, progress of FHB development, yield reduction, and models of host - pathogen interactions in theTriticum - Fusarium pathosystem. Significant correlations between different attributes of FHB were found forFusarium isolate 1 which is a moderate producer of DON (0.89 µg g(-1)). Weight of spike was significantly correlated with weight of kernels per spike (r = 0.93**) and with percentage of damaged kernels (r = - 0.87**), while FDK was highly correlated with RWKH (r = - 0.85*) and with DON content (r = 0.82*). Area under the disease progress curve was also found to be significantly correlated with DON content (r = 0.86*).

Ochratoxin A in porcine blood and in consumed feed samples.

The aim of the study was to estimate occurrence of ochratoxin A (OA) in feeds and the metabolite residues in porcine blood serum in Poland. Samples were collected in the period from February to May, 1999, in the southern Wielkopolska region. Altogether 40 and 45 samples of feed and porcine blood serum, respectively, were analyzed for OA. Percentage of samples contaminated with OA, both in case of feeds and blood, collected in the winter season was considerably higher than that for the spring season. The percentages for feeds were as follows: 47.6 and 26.3 %, while for porcine serum: 66.7 and 50.0 %, respectively winter and spring. In 25 % of cases ochratoxin A was present in both types of investigated material (feed, blood), whereas in 27.5 % of samples this metabolite was detected in blood only, or in 7.5 % only in the feed. The presence of OA was found neither in the feed nor in the serum in 40 % of all cases. In subgroups (feed, blood) the concentration in the whole collective of positive samples were in the range 0.3-13.5 ng/g and 0.3-69.5 ng/ml, respectively, while median values were 2.3 ng/g and 6.0 ng/ml. Only one feed and three porcine serum samples, were found to be contaminated at concentration levels higher than 10 ng/g or 10 ng/ml.

The effects of cereal substrate and temperature on production of beauvericin, moniliformin and fusaproliferin by Fusarium subglutinans ITEM-1434.

One strain of Fusarium subglutinans (ITEM-1434) isolated from maize ear rot in Poland was tested for the ability to synthesize moniliformin (MON), beauvericin (BEA) and fusaproliferin (FP) on six cereal substrates (wheat, rye, barley, oat, maize and rice kernels) for 3 weeks at 25 degrees C and on rice at three different temperatures (20, 25 and 30 degrees C). Most MON (497 micrograms/g) was produced on rice; most BEA (704 micrograms/g) on wheat or rice, and most FP (422 micrograms/g) on rye. When cultured on rice, F. subglutinans produced the highest levels of BEA and FP at 20-25 degrees C, while MON production was best at 30 degrees C.

Beauvericin production by Fusarium species.

Beauvericin is a cyclohexadepsipeptide mycotoxin which has insecticidal properties and which can induce apoptosis in mammalian cells. Beauvericin is produced by some entomo- and phytopathogenic Fusarium species (Fusarium proliferatum, F. semitectum, and F. subglutinans) and occurs naturally on corn and corn-based foods and feeds infected by Fusarium spp. We tested 94 Fusarium isolates belonging to 25 taxa, 21 in 6 of the 12 sections of the Fusarium genus and 4 that have been described recently, for the ability to produce beauvericin. Beauvericin was produced by the following species (with the number of toxigenic strains compared with the number of tested strains given in parentheses): Fusarium acuminatum var. acuminatum (1 of 4), Fusarium acuminatum var. armeniacum (1 of 3), F. anthophilum (1 of 2), F. avenaceum (1 of 6), F. beomiforme (1 of 1), F. dlamini (2 of 2), F. equiseti (2 of 3), F. longipes (1 of 2), F. nygamai (2 of 2), F. oxysporum (4 of 7), F. poae (4 of 4), F. sambucinum (12 of 14), and F. subglutinans (3 of 3). These results indicate that beauvericin is produced by many species in the genus Fusarium and that it may be a contaminant of cereals other than maize.

Simultaneous analysis of beauvericin and moniliformin in fungal cultures and in cereal grain samples.

Species ofFusarium subglutinans andFusarium proliferation have been found to produce two mycotoxins, beauvericin and moniliformin, under labolatory conditions as well as in infected ears. A method for simultaneous extraction, analysis and quantitation of both metabolites was elaborated. Recoveries were 85-97 % and 78-94 % for the first and the latter mycotoxin, respectively. Detection limit of beauvericin on high- performance thin- layer chromatography plates (Merck 5633) after exposure to iodine vapours was 3 µg/g and by high- performance liquid chromatography method 0.07 µg/g while moniliformin was analyzed at concentration level 1 µg/g by thin- layer chromatography and 0.05 µg/g by high- performance liquid chromatography method.

Biosynthesis of gibberellic acid (GA3) and mycotoxins by F. moniliforme sheldon and other species of Liseola section.

F. moniliforme and other species of Liseola section, F. culmorum, F. dlamini, and F. nygamai, were examined for their ability to produce gibberellic acid (GA3), fumonisins, trichothecenes, zearalenone, moniliformin, and bikaverin (TLC method). Gibberellic acid was produced by F. moniliforme strains in liquid medium and on rice kernels with a maximum concentration level of 470 mg/dm3 and 1 g/kg, respectively. No strain isolated in Poland produced GA3. High-yielding gibberellic acid strains produced neither trichothecenes and fumonisins nor other tested compounds. Also the rest of strains of examined species did not produce trichothecenes and other mycotoxins except for fumonisins which were found in rice cultures of F. moniliforme, F. proliferatum, and F. subglutinans. Bikaverin was produced by F. moniliforme always together with fumonisins. Filtrates of liquid cultures of gibberellin producing strains were tested for their toxicity to brine shrimps larvae (Artemia salina). It was found that GA3 presence does not increase toxicity of these filtrates.

Decomposition of ochratoxin A by heat and gamma-irradiation.

Up to 50% of initial amounts of 2 and 100 ng/ml ochratoxin A were decomposed after gamma-irradiation of solutions in water, in 2% aqueous NaCl or an aqueous solution of 2% NaCl and NaNO2. Ochratoxin A in these solutions was not decomposed, however, after heating at 20, 121 or 135 degrees C for 15 min.

Possible sources of ochratoxin A in human blood in Poland.

Samples of plant origin and human and porcine blood samples were screened over a long period for the presence of ochratoxin A. Of 1353 cereal samples, 11.7% contained the mycotoxin; of 1372 samples of feed, 1.5%; of 368 bread samples, 17.2%; of 215 flour samples, 22.3%; of 894 porcine serum samples, 37.4%; and of 1065 human serum samples, 7.2%. Seasonal variations in the natural occurrence of ochratoxin A were observed, with an increased percentage of positive samples in the spring. Individual daily intake of the mycotoxin, estimated on the basis of residues in human serum, was found to be 0.4 ng/g of food consumed.

Biosynthesis and preparation of fiveAlternaria metabolites.

Metabolites ofAlternaria alternata were produced on rice as a solid substrate, chosen out of 6 substrates as the most useful. Optimal methods of extraction, purification, and separation of 5 metabolites were elaborated, using liquid - liquid partition, column chromatography, and preparative TLC. Alternariol, alternariol methyl ether, and copper salt of tenuazonic acid were obtained as crystals, altertoxin and altenuene as a film.

Biosynthesis, isolation, purification and seperation of Zearalenone, deoxynivalenol and 15-Acetyldeoxynivalenol.

Fusarium graminearum KF-376 isolate was found to be able to form simultaneously three toxic metabolites: zearalenone (FF-2), deoxynivalenol (DON) and 15-acetyldeoxynivalenol (15-AcDON). Toxins were extracted with methanol - water 3:1 (v/v) and purified by liquid chromatography on charcoal - Kieselgel 60 column (preliminary) and Aluminiumoxid 90 column. Final separation of the metabolites was achived on Kieselgel 60 - Aluminiumoxid 90 column.

Biosynthesis, isolation, purification and separation of nivalenol, fusarenone - X and zearalenone.

Fusarium, graminearum KF 370 isolate is able to simultaneous biosynthesis of three toxic metabolites, namely: fusarenone-X (FUS), nivalenol (NIV) and zearalenone (F-2). After metabolites extraction with methanol - water (3:1) and defatting with n-heptane toxins were partitioned into chloroform layer. Purification of the? compounds was performed on Celite 545 - charcoal - Aluminiumoxid 90 column then metabolites were separated on Kieselgel 60 (200-300 mesh) column with developing solvent chloroform - methanol. This way FUS, NIV and F-2 were obtained as crystalline or high purity standards.

Do the pigments differ chemotaxonomically fungi belonging to genusFusarium?

Biosynthesis of bikaverin - red pigment responsible for characteristic colour ofFusarium cultures and known as vacuolation and aging factor - by 60Fusarium isolates belonging to 9 species was examined. We observed that bikaverin is a common metabolite produced by species of Liseola, Mar tiella, Elegans and Dlaminiella sections.Twenty nine isolates of fourFusarium species (F. moniliforme, F. subglutinans, F. proliferatum andF. anthophilum), belonging to the following Liseola section were investigated on their ability to biosynthesis of secondary metabolites bikaverin, 8-methylfusarubin, 3,8-dimethylfusarubin, 8-methylbostrycoidin, nectriafurone and fusarin C. All examined isolates of section Liseola formed bikaverin and 8-methylfusarubin, while 21 isolates additionally produced 8-methylbostrycoidin. OnlyF. moniliforme isolates were able to form fusarin C. We did not observe chemotaxonomical differences betweenFusarium, species according their ability to biosynthesis of such secondary metabolites as bikaverin, 8-methylfusarubin and 8-methylbostrycoidin.

Improved methods of zearalenone and moniliformin preparation.

Modified procedures of zearalenone and moniliformin preparation, using solid substrate (rice or corn kernels) has been developed. Preliminary purification of toxins by 1iquid-liquid partition was applied, followed by column chromatography on silicagel and charcoal. Final yield was about lg from 1kg of dry cultures of crystalline zearalenone and liophylized moniliformin o high purity.