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In developing Gallería mellonella larvae (reared at 30°C) three proteins of 74/ 76 and 81/82 kDa were identified. They represent a group of storage proteins (LHP proteins). In Galleria larvae, the development of which is arrested by low temperature (18°C)/ accumulation of the 74, 76 and 81/82 kDa proteins was detected in the hemolymph. The synthesis of 74 kDa and 76 kDa proteins started after 24 h, and that of about 80 kDa after 96 h following the transfer of larvae from 30°C to 18°C. 20-Hydroxyecdysone inhibited synthesis of the 74 and 76 kDa proteins in larvae exposed to low temperature. The arrest of development of Galleria larvae is associated with the synthesis and accumulation of storage proteins, and ecdysteroids are involved in these processes.
A rapid decrease in floristic biodiversity of agrocenoses has been observed in Europe for a half of century. A dynamic intensification of processes of crop production is considered one of the major reasons for shrinking of occurrence acreage and population number, or even extinction of numerous species with narrow ecological niche and high sensitivity to herbicides. These unfavourable transformations contribute to the gene pool restriction and necessity of species conservation. A representative of that group of plants is Illecebrum verticillatum (Caryophyllaceae) – a rare species endangered due to extinction in many European countries. Results of a study on decline of communities with Illecebrum verticillatum at the most northeastward sites in the Kałuszyn Upland (Podlasie Lowland, Eastern Poland) are presented. Observations were made on permanent plots for three periods (I – the years 1994–1997, period II – the years 2002–2004 and period III –the years 2008–2010) over the last 17 years. The material studied consisted of 136 phytosociological releves made by Braun-Blanquet method. Changes in phytoceoses with Illecebrum verticillatum were analysed and the habitat factors responsible for regression of these phytocenoses were identified. The degree of endangering of Illecebrum verticillatum in the area studied was evaluated on the basis of the frequency of occurrence, population abundance and genetic variation at the level of storage proteins in seeds by the modified SDS-PAGE method. Comparison of phytocenoses from different periods revealed a number of qualitative and quantitative differences. The number of sites of occurrence as well as population abundance of Illecebrum verticillatum have drastically decreased. Changes in the contribution of indicatory species (according to Ellenberg) were noted. In periods II and III a decrease in the contribution of hygrophilous and acidophilous species and an increase in that of nitrophilous species was observed. Significant changes in the structure of communities were confirmed by the calculated similarity indices (the most pronounced differences were observed between periods I and III). The phytocenoses were transformed towards degraded floristic composition, manifested by a decrease in the number of species in a plot, decrease in species diversity and increase in the index of domination. A significant increase in pH and nitrogen content at the habitats studied was noted. The phytocenoses reveal a replacement of nitrophilous for the eurytopic species. The factors having the strongest restricting effect on the occurrence of communities with Illecebrum verticillatum in the areas studied include: changes in the structure of agricultural use of land, increase in the contribution of maize in the structure of crops and intensification of production. At present 6 sites with Illecebrum verticillatum remain in the study area about 260 km2 (Kałuszyn Upland, Central-eastern Poland). Electrophoretic analysis of storage proteins in seeds of this speciesfrom these sites has shown high genetic similarity of these populations, irrespective of the distances between them (0–19% diversity among six the remaining populations). The diminished genetic pool of Illecebrum verticillatum population in this area indicates a need for the protection of this species.
Stachys annua is a short-lived archaeophyte. In Poland it has been classified as threatened with extinction (VU). It prefers carbonate soils and occurs as a weed in cropped and stubble fields in traditionally farmed areas. Study of the occurrence of Stachys annua in North-Eastern Poland was conducted in 2009–2012 at four sites where the species occupied a minimum area of 30 m² and occurred at each stage of a 4-year crop rotation (spring cereals, winter cereals, tuber crops and stubble fields). The floristically richest communities (25–34 species) were established in unploughed stubble fields, regardless of the habitat conditions. Phytocenoses with S. annua included rare species as demonstrated by high values of floristic value index (FV ranges from 25 to 36). Principle Component Analysis and Spearman rank correlations between plant traits and habitat conditions pointed to soil pH as the factor which determined S. annua phenotypic variation, in particular its height and seed production. The greatest phenotypic variation was found on the alkaline habitat, rich in nitrogen. On the other hand, the cluster analysis showed that the studied populations of inert nitrogen-poor habitats were the most similar. Electrophoretic analysis of storage proteins from S. annua seeds revealed a relatively high genetic similarity of studied populations which was reflected in the similarity coefficients — 0.76 and 0.61 by Dice and Jaccard, respectively. In the case of small or fragmented populations this poses a threat associated with inbreeding and genetic drift of S. annua, which indicates that populations of this species in the study area need to be protected from extinction.
The mechanisms underlying larval diapause in the wax moth (Galleria mellonella) is one of the most throughly studied aspects. At the low temperature of 18°C, the last instar larvae did not pupate but transferred to 30°C they initiated development and pupation in a circadian manner. Different types of surgical manipulations including head-ligation, nerve cord-severance, implantation of the brain, prothoracic glands, accompanied with ecdysteroid titre measurements indicated that diapausing arrest of larval development at 18°C might be due to the nervous inhibition of their prothoracic glands.
Ferritin is well known as the main intracellular iron storage protein in both prokaryotes and eukaryotes, keeping it in a soluble and non-toxic form, though the role of ferritin as a vaccine candidate in echinococcosis has not yet been delineated. Through our study, ferritin was cloned from Echinococcus granulosus and expressed in Escherichia coli. The recombinant E. granulosus ferritin (rEgferritin) has a molecular weight of 19 kDa and could be recognized by anti-mice serum in Western blotting. The specific antibody was detected by enzyme-linked immunosorbent assay. Mice vaccinated with rEgferritin and challenged intraperitoneally with E. granulosus protoscoleces revealed significant protective efficacy up to 85.6%, compared with the control group. Thus, rEgferritin could be a promising candidate as an effective vaccine to prevent the infection of echinococcosis.
Sixty-two DNA sequences for the coding regions of omega-secalin (ω-secalin) genes have been characterized from rye (Secale cereale L.), hexaploid and octoploid triticale (× Triticosecale Wittmack), and wheat (Triticum aestivum L.) 1BL/1RS translocation line. Only 19 out of the 62 ω-secalin gene sequences were full-length open reading frames (ORFs), which can be expressed into functional proteins. The other 43 DNA sequences were pseudogenes, as their ORFs were interrupted by one or a few stop codons or frameshift mutations. The 19 ω-secalin genes have a typical primary structure, which is different from wheat gliadins. There was no cysteine residue in ω-secalin proteins, and the potential celiac disease (CD) toxic epitope (PQQP) was identified to appear frequently in the repetitive domains. The ω-secalin genes from various cereal species shared high homology in their gene sequences. The ω-secalin gene family has involved fewer variations after the integration of the rye R chromosome or whole genome into the wheat or triticale genome. The higher Ka/Ks ratio (i.e. non-synonymous to synonymous substitutions per site) in ω-secalin pseudogenes than in ω-secalin ORFs indicate that the pseudogenes may be subject to a reduced selection pressure. Based on the conserved sequences of ω-secalin genes, it will be possible to manipulate the expression of this gene family in rye, triticale, or wheat 1BL/1RS translocation lines, to reduce its negative effects on grain quality.
Isopyrum thalictroides is classified as an indicator species of the so-called ‘old-growth forests’. It occurs in shady deciduous forests and is a characteristic species of the order Fagetalia silvaticae. In many parts of Europe and Poland, it is classified in Red Lists of endangered species with different threat levels. Studies of an occurrence of I. thalictroides were carried out in the years 2000–2002 and 2010–2012 to examine changes in the abundance and morphological and genetic diversity of populations inhabiting small mid-field forest fragments (populations 2–4) and a compact forest (1 population), all located in east central Poland. Isopyrum thalictroides cover declined drastically at all isolated sites (from 83 to 93%) whereas the whole species diversity of these phytocenoses increased. By contrast, in the compact forest both, the area occupied by I. thalictroides population and the total community composition only slightly changed over time. When I. thalictroides plants sampled from all studied sites were compared in terms of the biometrical characteristics, populations 3 and 4 were found to be most similar, population 1 was less similar and population 2 was the most different of all populations, probably due to strong anthropogenic pressure. Electrophoretic analysis of seed and leaf storage proteins of Isopyrum thalictroides obtained from the four sites demonstrated that the populations were quite similar genetically, no matter how distant they were from each another. Population 2 was the most diverse, followed by population 1 whereas populations 3 and 4 were the most similar. A decreasing genetic distance in the I. thalictroides population would lead to inbreeding as seed setting by the plants will be poorer and the seeds will be less viable, which will result in a lower number of plants per a given area. The decreased gene pool indicates that the population of I. thalictroides is threatened with extinction in this area. Therefore, it is warranted to undertake some conservation measures to protect the species; hence the need arises to monitor it.
Bromus secalinus L. is an annual speirochoric species growing in agrocenoses of winter crops. In the past, B. secalinus L. could be found throughout Poland. The regression of the species has caused it to be classified as a rare species threatened with extinction. The study was conducted in the 2007–2010 time period, in north-eastern Poland where a considerable increase in the number of sites and abundance of B. secalinus were observed. The plant material was collected from agrocenoses of winter crops, at 14 sites representing the habitat diversity of the species occurrence. Eight morphological features were taken into account when evaluating populations of B. secalinus. The morphological diversity of the populations of B. secalinus was correlated with different habitat conditions (type, pH of soil and cultivated plant). The populations growing on the sites with optimum trophic and moisture conditions as well as those populations growing in very poor conditions were found to differ the most. A comparison of B. secalinus was done and six groups of cluster similarities were found using the agglomeration method Electrophoretic analysis of seed storage proteins of B. secalinus L from the studied populations were performed using SDS-PAGE. Analysis revealed relatively high genetic polymorphism irrespective of whether genetic variation was compared between the populations from different sites or between the subpopulations from only site number 4. Three homologenous groups were formed which were related to the cultivated plant coverage, and partially, to the type of soil. In the investigated populations and subpopulations, protein bands of molecular weight from 8 to 68 kDa were observed. The SDS-PAGE method was found suitable for the assessment of genetic variation in populations of B. secalinus L from many sites as well as within the subpopulations from one site.
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