DNA barcoding in autotrophic euglenids: evaluation of COI and 18s rDNA

Autotrophic euglenids (Euglenophyceae) are a common and abundant group of microbial eukaryotes in freshwater habitats. They have a limited number of features, which can be observed using light microscopy, thus species identification is often problematic. Establishing a barcode for this group is therefore an important step toward the molecular identification of autotrophic euglenids. Based on the literature, we selected verified species and used a plethora of available methods to validate two molecular markers: COI and 18S rDNA (the whole sequence and three fragments separately) as potential DNA barcodes. Analyses of the COI gene were performed based on the data set of 43 sequences (42 obtained in this study) representing 24 species and the COI gene was discarded as a DNA barcode mainly due to a lack of universal primer sites. For 18S rDNA analyses we used a data set containing 263 sequences belonging to 86 taxonomically verified species. We demonstrated that the whole 18S rDNA is too long to be a useful marker, but from the three shorter analyzed variable regions we recommend variable regions V2V3 and V4 of 18S rDNA as autotrophic euglenid barcodes due to their high efficiency (above 95% and 90%, respectively).     

Modulating effect of a magnetic field on Saprolegnia parasitica,Coker, 1923 infecting trout (Salmo trutta,L.) eggs

The aim of study was to investigate the effects of static magnetic fields [1 mT (miliTesla), 5 and 10 mT] on Saprolegnia parasitica growth, development, and cytotoxicity in the infection of trout eggs in hatcheries under laboratory and industrial conditions. The egg envelope (SEM) structures resulting from infection with and development of S. parasitica are also presented. S. parasitica mycelium was cultured on a microbiological medium SDA in Petri dishes (4 ± 0.2°C, 97% humidity) exposed to a magnetic field and in a control, to assess the mycelium growth rate. Effects of the magnetic field on cytotoxicity of S. parasitica after a 21‐day incubation on SDA medium were analyzed using the colorimetric cytotoxicity test MTT. Eggs of brown trout Salmo trutta were infected with S. parasitica by inoculum and incubated in glass vessels (4 ± 0.2°C) in a magnetic field and a control. The degree of mycelium invasion of the egg envelopes and the percentage of egg mortality were recorded daily thoughout the period of embrionic development. The magnetic field effects on brown trout eggs infected by wild strains of fungus‐like organisms (FLO) in the hatchery (4°C ± 0.1) were also investigated. Changes in the structure of brown trout egg envelopes as a result of infection and development of S. parasitica were examined in a FIB/SEM. The effects of magnetic fields of 5 and 10 mT on slowing the growth of mycelium of S. parasitica in vitro were also observed. Determining biochemical properties of S. parasitica also showed the effects of the magnetic field in differentiating the cytotoxicity. All magnetic field values showed a distinct decrease from medium to low values of S. parasitica cytotoxicity; the most effective reduction was observed at 5 mT. Magnetic fields in all tested levels slowed development of the mycelium on the incubated trout eggs, resulting in a decrease in the number of eggs infected by S. parasitica and thus permitting a greater hatching success. Similar effects were observed in other hatching conditions where eggs were also exposed. No negative effects of magnetic field treatment on the condition of the newly‐hatched larvae were observed. The SEM and FIB (Focused Ion Beam) analyses revealed penetration of S. parasitica via radial canals of the envelope. The magnetic field had no effect on the structure of hyphae or sporangia of S. parasitica, but did affect the growth rate of mycelium on the egg surface.     

Dissecting the U,M, S and C genomes of wild relatives of bread wheat (Aegilops spp.) into chromosomes and exploring their synteny with wheat

Goat grasses (Aegilops spp.) contributed to the evolution of bread wheat and are important sources of genes and alleles for modern wheat improvement. However, their use in alien introgression breeding is hindered by poor knowledge of their genome structure and a lack of molecular tools. The analysis of large and complex genomes may be simplified by dissecting them into single chromosomes via flow cytometric sorting. In some species this is not possible due to similarities in relative DNA content among chromosomes within a karyotype. This work describes the distribution of GAA and ACG microsatellite repeats on chromosomes of the U, M, S and C genomes of Aegilops, and the use of microsatellite probes to label the chromosomes in suspension by fluorescence in situ hybridization (FISHIS). Bivariate flow cytometric analysis of chromosome DAPI fluorescence and fluorescence of FITC‐labelled microsatellites made it possible to discriminate all chromosomes and sort them with negligible contamination by other chromosomes. DNA of purified chromosomes was used as a template for polymerase chain reation (PCR) using Conserved Orthologous Set (COS) markers with known positions on wheat A, B and D genomes. Wheat–Aegilops macrosyntenic comparisons using COS markers revealed significant rearrangements in the U and C genomes, while the M and S genomes exhibited structure similar to wheat. Purified chromosome fractions provided an attractive resource to investigate the structure and evolution of the Aegilops genomes, and the COS markers assigned to Aegilops chromosomes will facilitate alien gene introgression into wheat.     

High domestic pig contribution to the local gene pool of free-living European wild boar: a case study in Poland

Rates of hybridization between wild and domesticated animals appear to be increasing worldwide. Recent results suggest that genetic introgression from domestic swine into European wild boar is much more common in local populations than expected, based on pan-European studies. Thus, we screened the genetic purity of 265 free-living wild boars from two hunting areas in Poland by genotyping the melanocortin receptor 1 gene (MC1R) for polymorphism. Unexpectedly, high numbers of individuals with domestic genes (24%) were identified. This suggests that mixed ancestry may be common in Polish wild boar. Among admixed individuals, backcrosses with domestic pig and/or introgressed wild boars were detected (2%). Multiple commercial domestic pig breeds are possibly involved in the introgression observed in the study populations. In addition, the absence of significant differences in the frequency of wild-type allele among two hunting areas suggests high dispersal of individuals and gene flow among populations. We conclude that further study is needed to better understand the mechanisms and sources of introgression in wild boars in Poland.     

Seasonal variations of the digestive tract of the Eurasian beaver <Emphasis Type="Italic">Castor fiber</Emphasis>

Forage availability for wild rodents varies with season. In turn, the composition of food can affect morphometric parameters of the digestive tract. This study was performed in Eurasian beavers (Castor fiber) whose population was close to extinction in most Eurasian countries, but has now increased. Due to the previous low number of studies, information about the effect of forage availability on the digestive tract morphology has previously been lacking. This study was performed using beavers captured from the natural environment during three seasons of different forage availability: winter, summer and autumn. It was found that the diet of the beaver varied during the year; in winter it was dominated by woody material consisting of willow shoots, whereas in summer the diet was primarily herbs, grass and leaves. Season also affected the mass of digested contents of the digestive tract. The digestive content increased in the caecum and colon in winter and autumn, when poor-quality food dominated the beaver’s diet. The results indicated that the digestive tract parameters of beavers varied based on the composition of available forage.     

In vitro activity of micafungin against biofilms of <Emphasis Type="Italic">Candida albicans</Emphasis>, <Emphasis Type="Italic">Candida glabrata</Emphasis>, and <Emphasis Type="Italic">Candida parapsilosis</Emphasis> at different stages of maturation

Candida spp. is able to form a biofilm, which is considered resistant to the majority of antifungals used in medicine. The aim of this study was to evaluate the in vitro activity of micafungin against Candida spp. biofilms at different stages of their maturation (2, 6, and 24 h). We assessed the inhibitory effect of micafungin against 78 clinical isolates of Candida spp., growing as planktonic or sessile cells, by widely recommended broth microdilution method. The in vitro effect on sessile cells viability was evaluated by colorimetric reduction assay. All examined strains were susceptible or intermediate to micafungin when growing as planktonic cells. At the early stages of biofilm maturation, from 11 (39.3%) to 20 (100%), tested strains, depending on the species, exhibited sessile minimal inhibitory concentrations (SMICs) of micafungin at ≤ 2 mg/L. For 24-h-old Candida spp. biofilms, from 3 (10.7%) to 20 (100%) of the tested strains displayed SMICs of micafungin at ≤ 2 mg/L. Our findings confirm that micafungin exhibits high potential anti-Candida-biofilm activity. However, this effect does not comprise all Candida species and strains. All strains were susceptible or intermediate to micafungin when growing as planktonic cells, but for biofilms, micafungin displays species- and strain-specific activity. Paradoxical growth of C. albicans and C. parapsilosis was observed. Antifungal susceptibility testing of Candida spp. biofilms would be the best solution, but to date, no reference method is available. The strongest antibiofilm activity of micafungin is observed at early stages of biofilm formation. Possibly, micafungin could be considered as an effective agent for prevention of biofilm-associated candidiasis, especially catheter-related candidaemia.     

Circular movement of honey bee spermatozoa inside spermatheca

It is believed that in honey bees spermatozoa stored inside the spermatheca remain motionless, however, some studies have reported the contrary. To observe behaviour of spermatozoa inside spermathecae, we have instrumentally inseminated queens with spermatozoa stained with fluorescent stains. During the first 8 h after insemination movement of the spermatozoa was stationary, without fast forward movement. Later, we observed circular movement of the spermatozoa inside spermathecae. Numerous circles were visible at one time. The circles were located close to the spermathecal wall. Movement of the spermatozoa was also observed in spermathecae of naturally inseminated queens. The marble-like pattern of the spermathecae was changing. The changes were slow and well visible only when video recordings were played at high speed.     

Restoration of hydro-ecological conditions in Carpathian forested mountain fens

The research was designed to assess benefits of passive restoration, consisting of blocking from drainage ditches and in effect raise the groundwater level, its influence on properties of soil, water, species of plants and mesofauna in the fen Caltho-Alnetum community. The research was carried out in Outer Flysh Carpathians, the area of the Babiogórski National Park (Poland) in 2011–2014. It was established that the degraded communities showed positive reaction to an attempt to restore the original groundwater level. The increase in the groundwater level changed chemical properties of soil and water of the community such as: pH, sorption properties and the ionic composition of groundwater. Changes in habitat conditions resulted in different species composition of soil mesofauna and plants growing in the restorative community.     

Bioaccessibility of phenolic compounds,lutein, and bioelements of preparations containing <Emphasis Type="Italic">Chlorella vulgaris</Emphasis> in artificial digestive juices

Chlorella vulgaris Beijerinck is a spherical, green alga belonging to the genus Chlorella and family Chlorellaceae. It has high nutritional value and shows multiple biological effects. Dietary supplements that contain extracts of C. vulgaris are sold in the form of tablets, capsules, powders, and aqueous solutions. To the best of our knowledge, this is the first study to determine the content of bioelements (zinc, iron, and magnesium), phenolic compounds, and lutein before and after incubation with artificial digestive juices from preparations containing C. vulgaris. In this study, we used commercial preparations in the form of powder and tablets. The samples were incubated in artificial gastric juice and then in artificial intestinal juice for 30 and 90 min. The contents of bioelements were determined by using the flame atomic absorption spectrometric method. Lutein and phenolic compounds were analyzed by high-pressure liquid chromatography. We also aimed to evaluate the quality of chlorella-containing formulations by using the methods described in the European Pharmacopoeia 8th edition. According to the results, the preparations containing C. vulgaris demonstrated the presence of phenolic compounds and lutein. Therefore, daily supplementation of preparations containing C. vulgaris substantiates its usefulness for humans. The qualitative composition of the examined organic substances and bioelements was found to be in accordance with the manufacturer’s declarations on the packaging containing C. vulgaris compared with the control samples; however, the contents of bioelements were found to be negligible after incubation with artificial digestive juices. This shows that the examined preparations containing C. vulgaris are not good sources of bioelements such as zinc, iron, or magnesium.