Decorin concentrations in canine normal and neoplastic mammary gland tissues

In the present study, the concentration of decorin in canine normal and neoplastic mammary gland tissues was examined to understand the potential role of decorin in development and progression of canine mammary tumours. The homogenates of 48 mammary gland tumours (10 benign and 38 malignant) and 10 samples of normal canine mammary gland tissue were used in the study. The presence and quantification of decorin was examined in the homogenates using Western blot and specific canine ELISA. Western blotting confirmed the presence of decorin both in the normal mammary gland tissues and in the mammary gland tumours. The concentration of decorin was significantly higher (p < .05) in the benign tumours and non-metastatic malignant tumours than in the normal mammary gland. The concentration of decorin was significantly lower (p < .05) in the malignant tumours with metastasis to regional lymph nodes compared with benign tumours and non-metastatic malignant tumours. No significant differences were found in the level of decorin between the benign and the non-metastatic malignant tumours. Both the histological type of malignant tumours and the histological grade did not significantly affect the concentration of decorin. These findings suggest that neoplastic transformation in the canine mammary gland leads to increase in the decorin protein synthesis. The reducing decorin concentration in canine malignant mammary tumours appears to facilitate the metastatic spread of these tumours.     

Effects of excessive dietary zinc or zinc/cadmium and tapeworm infection on the biochemical parameters in rats

The main objective of this study was to determine which biochemical blood parameters can serve as indicators of Zn or Zn/Cd burden and tapeworm infection. This study was performed on 44 Wistar male rats during a 6-week period, when rats were or were not fed a zinc/cadmium rich diet and were or were not infected with tapeworms (Hymenolepis diminuta). Total protein, albumin, urea, glucose, triacylglycerols, non-esterified fatty acids, cholesterol, alkaline phosphatase, aspartate aminotransferase, uric acid, Mg, Ca, P and Zn levels were analysed. Control rats with tapeworm infection had significantly higher (p ≤ 0.05) total protein, urea and phosphorus concentrations than did rats unaffected by any experimental factor. Rats given overdoses of zinc lactate exhibited significantly lower glucose levels than did the other rats, especially those infected with tapeworms. Low glucose level in uninfected rats indicate a Zn overdose; high doses of zinc lactate likely decrease levels of glucose via cortisol, which is released during stress. Rats fed the Zn/Cd hyperaccumulating plant Arabidopsis halleri and infected with tapeworms had significantly higher (p ≤ 0.01) cholesterol and urea levels but lower zinc, triacylglycerol, and alkaline phosphatase levels than did rats fed the same diet but free of tapeworms. The increase of alkaline phosphatase level in uninfected rats may indicate both Zn/Cd burden and rat liver damage. Overall, this study not only supports the theory that H. diminuta can serve as a promising model for helminth therapy of the host mammal but also confirmed that this tapeworm is capable to protect somehow the host organism from the harmful effects of heavy metals.     

Plague reservoir species throughout the world

Plague has been known since ancient times as a re-emerging infectious disease, causing considerable socioeconomic burden in regional hotspots. To better understand the epidemiological cycle of the causative agent of the plague, its potential occurrence, and possible future dispersion, one must carefully consider the taxonomy, distribution, and ecological requirements of reservoir-species in relation either to natural or human-driven changes (e.g. climate change or urbanization). In recent years, the depth of knowledge on species taxonomy and species composition in different landscapes has undergone a dramatic expansion, driven by modern taxonomic methods such as synthetic surveys that take into consideration morphology, genetics, and the ecological setting of captured animals to establish their species identities. Here, we consider the recent taxonomic changes of the rodent species in known plague reservoirs and detail their distribution across the world, with a particular focus on those rodents considered to be keystone host species. A complete checklist of all known plague-infectable vertebrates living in plague foci is provided as a Supporting Information table.     

Heritability estimates for processing and quality traits in common carp (Cyprinus carpio L.) using a molecular pedigree

Heritability estimates with a microsatellite parentage assignment based pedigree are of special interest in common carp cultured under traditional pond conditions. This method reduces common environment effects as all families can be grown immediately after hatching mixed in the same pond. We applied this method to study genetics of growth and processing traits in common carp at market size (1.5 kg and more). The experimental progeny was established by crossing 147 two-year old males and 8 females (six to eight-year old) of Hungarian synthetic mirror carp population. The fish grew up through three vegetation seasons and at the end a sample of 331 fish was examined for biometrical traits (standard length, body weight, relative head length, relative body height, relative body width), percent fat and processing traits (% processed body, % fillets with skin, % fillets without skin). It was shown that sex had a significant effect on most traits: females were larger and fatter than males, and they had both higher percent processed body and percent fillet with skin. Standard length, body weight, percent fat and relative head length had a high heritability (> 0.5), while relative body height, relative body width, percent processed body and fillet yields had a medium heritability (0.2–0.5). We found relatively high positive genetic correlations between body size (standard length and body weight) and percent fat (0.71 and 0.59, respectively), favourable genetic correlations between body size and percent processed body (0.69 for standard length and 0.74 for body weight) and between body size and fillet yields (0.50–0.77). Genetic correlations between body size and body shape (relative head length, relative body height and relative body width) were weak to moderate, thus selection for better growth should have little impact towards more rotund shape. Relative head length had strong negative correlation (− 0.7 to − 0.9) with percent fat, percent processed body and percent fillet yields. This means that indirect selection for reduced relative head length should be effective in improving of fillet yield.     

Avena fatua L. subsp. fatua v. glabrata Peterm. subv. pseudo-basifixa Thell. as a source of crown rust resistance genes

Summary An accession of Avena fatua L. subsp. fatua v. glabrata Peterm. subv. pseudo-basifixa Thell. (A. fatua L. CS Sel. No. 1), collected in Czechoslovakia in 1971, was found to be resistant to a wide range of crown rust races. Analyses of crosses of this oat with cvs. Weikuss, Leanda, Mona, Rodney A, Rodney B, Rodney M, Dodge and K 316 indicated that the resistance of A. fatua CS Sel. No. 1 is conditioned by one recessive gene which is in interaction with one partially dominant gene with additive effect. The expression of rust reaction was affected by temperature. The crown rust resistance genes of A. fatua L. CS Sel. No. 1 were non-allelic with stem rust resistance genes Pg-2 (A) and Pg-4(B).     

Variation in effective pollination rates in relation to the spatial and temporal distribution of pollen release in rejuvenated perennial ryegrass

Genebank accessions stored as seed populations require periodic rejuvenation in order to maintain sufficient numbers of viable seeds. During rejuvenation the genetic composition of accessions may be altered for a variety of reasons, of which variation in pollination rates between plants is the least understood. In the present study, a paternity exclusion analysis was performed on a rejuvenated accession of perennial ryegrass. In addition, flowering data of the 49 parental plants were collected during the flowering season. The aim of the study was to determine how accurate variation in pollination rates between plants can be predicted from data on the spatial and temporal distribution of pollen release. The parental population and a total of 551 offspring from 12 progeny arrays were genotyped by means of molecular analysis. Using 25 microsatellites, paternity was identified for 81.9% of the offspring, while remaining ambiguities were resolved by AFLP analysis, except in four cases. Within the total sample 9 cases of contamination were observed. Mating within the study population was clearly non-random, as 61.9% of the identified pollen donors were located within 1 m distance from the mother plant. Observed pollination rates were very well described by an inverse quadratic function of inter-plant distance between potential mating pairs. Incorporation of the recorded flowering data in the calculation of expected pollination rates improved the goodness of fit with observed values by only 0.77%. Suggestions to reduce the variance in paternal contributions were presented. However, contamination was considered more threatening to the genetic integrity of perennial ryegrass germplasm than variation in pollination rates between plants, and indicated the need for improved measures to avoid gene flow from other germplasm.     

First report of a 16SrIII-B subgroup phytoplasma associated with leaf reddening, virescence and phyllody of purple coneflower

Purple coneflower plants showing leaf reddening and flower abnormalities were observed in South Bohemia (Czech Republic). Transmission electron microscopy observations showed phytoplasmas in sieve cells of symptomatic plants but not in healthy ones. Polymerase chain reactions with universal and group specific phytoplasma primers followed by restriction fragment length polymorphism analyses of 16S rDNA allowed us to classify the detected phytoplasmas into the X-disease group, ribosomal subgroup 16SrIII-B. Sequence analyses of the 16S-23S ribosomal operon (1684 bp), ribosomal protein L15, and protein translocase genes (1566 bp) confirmed the closest relationship with phytoplasmas belonging to the 16SrIII ribosomal group, specifically the 16SrIII-B subgroup. The current study reports purple coneflower as a new host for the X-disease phytoplasma group in the Czech Republic and worldwide.     

Asymmetric relationship between grasses and forbs: results from a field experiment under nutrient limitation

We compared the role of grasses and forbs in managed grassland under nutrient‐poor conditions via the experimental removal of one of these two species groups and an evaluation of the removal effects over a 5‐year chronosequence (beginning 4 years after removal start), focusing on above‐ground biomass and community composition. There was evidence for the complementarity of grasses and forbs, as shown by better relative performance of both groups in the mixture, measured as the proportional deviation of their above‐ground biomass from that predicted using single‐group plots. Relative performance of forbs was better than that of grasses and did not change significantly throughout the experiment. Relative performance of grasses decreased, reaching a minimum value of 0·03, but then increased to 0·71, in parallel with increasing legume proportion in the above‐ground biomass (from 0·9 to 5·1%). The botanical composition of the grass group did not respond to forb removal. Among the forbs, subordinate species sensitive to light competition became more abundant after removal of grasses; the forb species richness increased on average by 1·6 species per plot. Our results show that the composition and diversity of the forb group is affected by the presence of grasses, and the presence of forbs in a grassland community assures higher temporal stability in above‐ground production. Under increasing depletion of soil nutrients, the grasses derive substantial benefits from the presence of legume species and possibly also from the other forb species. The study supports the need for realistic, long‐term experiments to better understand plant community dynamics.