Environmental factors associated with the distribution of floodwater mosquito eggs in irrigated fields in Wrocław,Poland

A survey of distribution patterns of floodwater mosquito eggs related to environmental conditions such as moisture and plant associations was conducted by using soil samples from irrigated fields in Wroc?aw, Poland. Mosquito egg distribution was determined by repeatedly flooding the soil samples with aerated water at a temperature of 25° C. Under laboratory conditions, hatching in installments of Aedes caspius (Pallas) and Aedes vexans (Meigen) were commonly observed. The results show that ～75% of the larvae of Ae. caspius and Ae. vexans hatched after the first flooding under summer‐like conditions, whereas, following the second and third flooding, the numbers of hatched larvae were significantly lower. In our study, within one intermediate flooded field, a total of 66 plant species was identified and classified into six communities. All vegetation types were associated by varied egg densities and showed differences both in richness and Shannon‐Wiener diversity index as well as in ecological indices for moisture, soil reaction, and nutrient level. Small changes in elevation along the slope within the study area showed a large difference in the distribution of mosquito eggs. The highest average egg density was observed in zones with high occurrence of Phalaris arundinacea, usually prevalent in intermediate flooded and fertile areas. Knowledge of the indicators for the distribution of floodwater mosquito eggs in temporary breeding sites may be essential for organizing a successful, integrated mosquito control program with special regard to microbial control agents.     

Statistical modelling of growth using a mixed model with orthogonal polynomials

In statistical modelling, the effects of single-nucleotide polymorphisms (SNPs) are often regarded as time-independent. However, for traits recorded repeatedly, it is very interesting to investigate the behaviour of gene effects over time. In the analysis, simulated data from the 13th QTL-MAS Workshop (Wageningen, The Netherlands, April 2009) was used and the major goal was the modelling of genetic effects as time-dependent. For this purpose, a mixed model which describes each effect using the third-order Legendre orthogonal polynomials, in order to account for the correlation between consecutive measurements, is fitted. In this model, SNPs are modelled as fixed, while the environment is modelled as random effects. The maximum likelihood estimates of model parameters are obtained by the expectation–maximisation (EM) algorithm and the significance of the additive SNP effects is based on the likelihood ratio test, with p-values corrected for multiple testing. For each significant SNP, the percentage of the total variance contributed by this SNP is calculated. Moreover, by using a model which simultaneously incorporates effects of all of the SNPs, the prediction of future yields is conducted. As a result, 179 from the total of 453 SNPs covering 16 out of 18 true quantitative trait loci (QTL) were selected. The correlation between predicted and true breeding values was 0.73 for the data set with all SNPs and 0.84 for the data set with selected SNPs. In conclusion, we showed that a longitudinal approach allows for estimating changes of the variance contributed by each SNP over time and demonstrated that, for prediction, the pre-selection of SNPs plays an important role.     

Practical application of daughter yield deviations in dairy cattle breeding

Daughter yield deviations (DYDs) of bulls and yield deviations (YDs) of cows, besides estimated breeding values (EBVs), are standard measures of animals' genetic merits in routine genetic evaluations worldwide. In this contribution, we first point out differences and similarities between DYDs and EBVs calculated for milk, fat and protein yields. While the latter measure represents the additive polygenic value of an animal, the former consists of both the additive polygenic and residual components. Then, a summary of DYDs and YDs calculated for the Polish population of dairy cattle is presented. The estimated correlations between DYDs and EBVs are generally high, but vary considerably depending on the minimum number of daughters used for calculation of DYDs and on the accuracy of calculated DYDs. Using DYDs estimated for each production year for 16 452 bulls, we demonstrate how to use DYDs for the validation of genetic trend estimated in the model used for genetic evaluation. Based on genotypic data of 252 bulls, we show that DYDs can be used for the estimation of candidate gene effects. For each of the yield traits, the within-bull genetic trend was relatively high, ranging between 1.39% of genetic standard deviation per production year for milk and 7.67% of genetic standard deviation per production year for fat, both in the 2nd lactation. Out of 8 polymorphisms tested, 5 showed a significant correlation with DYD, with the highest effect attributed to the polymorphism within the leptin receptor gene, whose additive effect was estimated as 247.33 kg of milk at 2nd parity.     

Copper(II) complexes of Neobelliera Bullata Trypsin Modulating Oostatic Factor and its analogues

The stoichiometry, stability constants and solution structure of the complexes formed in the reaction of copper(II) with hexapeptide NPTNLH, i.e. the Neobelliera Bullata Trypsin Modulating Oostatic Factor (Neb-TMOF), and its analogues DPTNLH, Ac-NPTNLH and Ac-DPTNLH have been determined by potentiometric, UV-visible, CD and EPR spectroscopic methods. Upon raising pH for Ac-NPTNLH and Ac-DPTNLH peptides, copper(II) coordination starts from the imidazole nitrogen of the His⁶; afterwards three deprotonated amide nitrogens are progressively involved in metal ions coordination. In a wide pH range of 4.5-8.5 for the NPTNLH and DPTNLH ligands the CuL complex dominates with the imidazole nitrogen of His⁶ coordinated to form a macrochelate. The N-terminal amino group of the NPTNLH and DPTNLH peptides takes part in the coordination of the metal ion in the CuL, CuH₋₁L and CuH₋₂L complexes. However, at pH above 9 the CuH₋₃L complex with the {N_Im, 3N⁻} coordination mode is formed. For the CuH₋₂L complex the spectroscopic data clearly indicate the 4N {NH₂, CO or COO⁻, 2N⁻, N_Im} bonding mode with the axial coordination of the N-terminal amine group to the metal ion.     

Helminth infections in faecal samples of wolves Canis lupus L. from the western Beskidy Mountains in southern Poland

Eighty-nine samples of grey wolf (Canis lupus L.) faeces were collected between 2002 and 2004 from two areas in the western Beskidy Mts (south Poland). Helminth eggs were observed in 56.2% of faeces examined. These included: Alaria alata (2.2%), taeniid eggs (11.2%), Toxocara canis (5.6%), Toxascaris leonina (1.1%), Eucoleus aerophilus (14.6%), Ancylostoma caninum (12.3%), Uncinaria stenocephala (37%) and unidentified roundworm eggs of the family Strongyloididae (1.1%). Eucoleus aerophilus is recorded for the first time from Poland. The results are compared with the helminth fauna of other wolf populations in Europe.     

Reptilian transferrins: evolution of disulphide bridges and conservation of iron-binding center

Transferrins, found in invertebrates and vertebrates, form a physiologically important family of proteins playing a major role in iron acquisition and transport, defense against microbial pathogens, growth and differentiation. These proteins are bilobal in structure and each lobe is composed of two domains divided by a cleft harboring an iron atom. Vertebrate transferrins comprise of serotransferrins, lactoferrins and ovotransferrins. In mammals serotransferrins transport iron in physiological fluids and deliver it to cells, while lactoferrins scavenge iron, limiting its availability to invading microbes. In oviparous vertebrates there is only one transferrin gene, expressed either in the liver to be delivered to physiological fluids as serotransferrin, or in the oviduct with a final localization in egg white as ovotransferrin. Being products of one gene sero- and ovotransferrin are identical at the amino-acid sequence level but with different, cell specific glycosylation patterns. Our knowledge of the mechanisms of transferrin iron binding and release is based on sequence and structural data obtained for human serotransferrin and hen and duck ovotransferrins. No sequence information about other ovotransferrins was available until our recent publication of turkey, ostrich, and red-eared turtle (TtrF) ovotransferrin mRNA sequences [Ciuraszkiewicz, J., Olczak, M., Watorek, W., 2006. Isolation, cloning and sequencing of transferrins from red-eared turtle, African ostrich and turkey. Comp. Biochem. Physiol. 143 B, 301-310]. In the present paper, ten new reptilian mRNA transferrin sequences obtained from the Nile crocodile (NtrF), bearded dragon (BtrF), Cuban brown anole (AtrF), veiled and Mediterranean chameleons (VtrF and KtrF), sand lizard (StrF), leopard gecko (LtrF), Burmese python (PtrF), African house snake (HtrF), and grass snake (GtrF) are presented and analyzed. Nile crocodile and red-eared turtle transferrins have a disulphide bridge pattern identical to known bird homologues. A partially different disulphide bridge pattern was found in the Squamata (snakes and lizards). The possibility of a unique interdomain disulphide bridge was predicted for LtrF. Differences were found in iron-binding centers from those of previously known transferrins. Substitutions were found in the iron-chelating residues of StrF and TtrF and in the synergistic anion-binding residues of NtrF. In snakes, the transferrin (PtrF, HtrF and GtrF) N-lobe "dilysine trigger" occurring in all other known transferrins was not found, which indicates a different mechanism of iron release.     

Preservation of tomcat (Felis catus) semen in variable temperatures

The aim of our study was to estimate the viability of cat epididymal sperm in short time storage at +4 degrees C and in long term storage at -196 degrees C and to assess the percentage of live sperm in fresh semen using eosin/nigrosin staining compared to the flow cytometry method. The testes with epididymides were obtained after routine castration procedure. The sperm for further research were collected after flushing the epididymides using extender consist of: Tris 2.4 g, citric acid 1.4 g, glucose 0.8 g, 0.06% (w/v) Na-benzylpenicillin, 0.1% (w/v) streptomycin sulphate and distilled water. Half of each sample was equilibrated with the dilution and loaded in 0.25 ml plastic straws. The straws were placed on a rack in liquid nitrogen vapour at -120 degrees C for 10 min, plunged in liquid nitrogen for 10 min, replaced to marked goblets and loaded into canes for long term storage in liquid nitrogen at -196 degrees C. Sixty percent of motile spermatozoa was accomplished after thawing. However, the percentage of the sperm with intact acrosomes was decreased and the share of cells with midpiece and tail defects was increased. The storage of sperm flushed from epididymides at +4 degrees C for a short time and the usage of sperm during 2-3 days after collection seems to be better than cryopreservation. In our study, normospermia was present in 72.7 +/- 8.8% of fresh semen. The most common defect was the presence of distal droplets, imperfect heads or abnormal acrosomal outline. The motility of fresh sperm flushed from epididymides achieved 77.9 +/- 6.8%. The viability of sperm amounting to 52.5 +/- 13.8% was achieved on third day of conservation in the liquid extender. The percentage of viable sperm in fresh epididymal spermatozoa was 84.9 +/- 7.8%. Compared to these results, the percentage of live cells using SYBR-14/propidium iodide staining was insignificantly lower (82.2 +/- 8%). The live, non-apoptotic cells were 79.0 +/- 7.8%. The share of live, early-apoptotic spermatozoa and late-apoptotic spermatozoa was, respectively, 2 +/- 1.4% and 1.5 +/- 0.9%. The viability of sperm estimated by eosin/nigrosin staining was confirmed by the flow cytometry method. There was no statistical differences between the staining. The usage of apoptosis detection kit revealed, that the percentage of early-apoptotic and late-apoptotic cells was insignificant.     

Effect of norflurazon on resorcinolic lipid metabolism in rye seedlings

Norflurazon is a selective pyridazinone herbicide excessively employed in the control of many annual grasses and broad-leaved weeds. This chemical causes plant bleaching due to the inhibition of the carotenoid pigment biogenesis as well as induces irreparable changes to chloroplasts, which are considered the organelles where the biosynthesis of resorcinolic lipids takes place. Resorcinolic lipids, a group of phenolic compounds, constitute not only an essential part of the plant antifungal defense system, but also are an important component of the human cereal diet. The aim of this study was to investigate the effect of norflurazon on the biosynthesis of resorcinolic lipids in 5-day-old rye plants (Secale cereale L.) that were grown at three different temperatures under light or dark conditions. At all tested temperatures, norflurazon decreased the fresh biomass of light-grown rye seedlings and increased the weight of plants grown in darkness. Compared with respective controls, this herbicide caused an increase in total content of alkylresorcinols in both green and etiolated plants with the exception of dark-grown norflurazon-treated rye at 29 degrees C. The general level of saturated homologues was markedly decreased by norflurazon in all etiolated plants and in light-grown seedlings at 15 degrees C. Independent of thermal and light conditions, in all norflurazon-treated samples two alkylresorcinol derivatives predominated: 1,3-dihydroxy-5-n-heptadecylbenzene and 1,3-dihydroxy-5-n-nonadecylbenzene. Thus, our results suggest that norflurazon affected the metabolism of alkylresorcinols in rye seedlings and its action was dependent on external stimuli.