Zbigniew Adamski

The caudal regeneration blastema is an accumulation of rapidly proliferating stem cells in the flatworm Macrostomum lignano

BackgroundMacrostomum lignano is a small free-living flatworm capable of regenerating all body parts posterior of the pharynx and anterior to the brain. We quantified the cellular composition of the caudal-most body region, the tail plate, and investigated regeneration of the tail plate in vivo and in semithin sections labeled with bromodeoxyuridine, a marker for stem cells (neoblasts) in S-phase.ResultsThe tail plate accomodates the male genital apparatus and consists of about 3,100 cells, about half of which are epidermal cells. A distinct regeneration blastema, characterized by a local accumulation of rapidly proliferating neoblasts and consisting of about 420 cells (excluding epidermal cells), was formed 24 hours after amputation. Differentiated cells in the blastema were observed two days after amputation (with about 920 blastema cells), while the male genital apparatus required four to five days for full differentiation. At all time points, mitoses were found within the blastema. At the place of organ differentiation, neoblasts did not replicate or divide. After three days, the blastema was made of about 1420 cells and gradually transformed into organ primordia, while the proliferation rate decreased. The cell number of the tail plate, including about 960 epidermal cells, was restored to 75% at this time point.ConclusionRegeneration after artificial amputation of the tail plate of adult specimens of Macrostomum lignano involves wound healing and the formation of a regeneration blastema. Neoblasts undergo extensive proliferation within the blastema. Proliferation patterns of S-phase neoblasts indicate that neoblasts are either determined to follow a specific cell fate not before, but after going through S-phase, or that they can be redetermined after S-phase. In pulse-chase experiments, dispersed distribution of label suggests that S-phase labeled progenitor cells of the male genital apparatus undergo further proliferation before differentiation, in contrast to progenitor cells of epidermal cells. Mitotic activity and proliferation within the blastema is a feature of M. lignano shared with many other regenerating animals.

Effect of boric acid on antioxidant enzyme activity, lipid peroxidation, and ultrastructure of midgut and fat body of Galleria mellonella

Boric acid is widely used as an insecticide, acaricide, herbicide, and fungicide and also during various industrial processings. Hence, numerous populations are subjects to this toxic compound. Its action on animals is still not fully known and understood. We examined the effect of boric acid on larvae of greater wax moth (Galleria mellonella). The chemical appeared to be toxic for larvae, usually in a concentration-dependent manner. Exposed groups revealed increased lipid peroxidation and altered activity of catalase, superoxide dismutase, glutathione S-transferase, and glutathione peroxidase. We also observed changes of ultrastructure, which were in tune with biochemical assays. We suggest that boric acid has a broad mode of action, which may affect exposed larvae, and even if sublethal, they may lead to disturbances within exposed populations.

Inheritance of chorionic malformations and insecticide resistance by Spodoptera exigua

Abstract:  Effect of exposure to the organophosphorus insecticide – fenitrothion [O,O‐dimethyl‐O‐(4‐nitro‐3‐methyl)phenyl] – on four generations of Spodoptera exigua Hübner (Lep., Noctuidae) larvae, with regard to the mortality and structure of the chorion of eggs laid was tested. Generations varied in the total mortality rate, although all of them showed some survival rate. The third and the fourth generations showed the lowest mortality among tested ones. Exposure to fenitrothion caused malformations in eggs. The chorion revealed cracks and diminutions of the outer layer. The quality and quantity of malformations increased proportional to the duration of exposure, e.g. the second exposed generation reveald more prominent changes than the first one. Malformations were observed in the next generations, which were not exposed to pesticide. The follicular cells, which are responsible for the structure and sculpture of the eggshell, must have inherited the malforming mechanism. Most probably, malformation takes place during the late development of eggs in the ovarioles.

The influence of dietary α-solanine on the waxmoth Galleria mellonella L.

Plant allelochemicals are nonnutritional chemicals that interfere with the biology of herbivores. We posed the hypothesis that ingestion of a glycoalkaloid allelochemical, α-solanine, impairs biological parameters of greater wax moths Galleria mellonella. To test this idea, we reared wax moths on artificial diets with 0.015, 0.15, or 1.5 mg/100 g diet of α-solanine. Addition of α-solanine to the diet affected survival of seventh-instar larvae, pupae, and adults; and female fecundity and fertility. The diet containing the highest α-solanine concentration led to decreased survivorship, fecundity, and fertility. The diets supplemented with α-solanine led to increased malondialdehyde and protein carbonyl contents in midgut and fat body and the effect was dose-dependent. Dietary α-solanine led to increased midgut glutathione S-transferase activity and to decreased fat body glutathione S-transferase activitiy. We infer from these findings that α-solanine influences life history parameters and antioxidative enzyme activities in the midgut and fat body of G. mellonella.

Cardioactive properties of Solanaceae plant extracts and pure glycoalkaloids on Zophobas atratus.

Glycoalkaloids, the biologically active secondary metabolites produced by Solanaceae plants, are natural defenses against animals, insects and fungi. In this paper, the effects of glycoalkaloids present in extracts of Solanaceae plants (potato, tomato and black nightshade) or pure commercial glycoalkaloids on the coleopteran Zophobas atratus F. were evaluated by in vitro and in vivo bioassays using heart experimental models. Each tested extract induced a dose‐dependent cardioinhibitory effect. The perfusion of Zophobas atratus semi‐isolated heart using the highest potato and tomato extract concentration (1 mmol/L) caused irreversible cardiac arrests, while extract from black nightshade produced fast but reversible arrests. Pure commercial glycoalkaloids caused similar but less evident effects compared with extracts. Our results showed that the bioactivity of tested compounds depended on their structure and suggested the existence of synergistic interactions when combinations of the main glycoalkaloids of potato and black nightshade were used for trials. Surprisingly, injection of tomato and potato extracts in 1‐day‐old pupae of Zophobas atratus induced reversible positive chronotropic effects and decreased the duration of the both phases (anterograde and retrograde) of the heart contractile activity. Furthermore, these extracts affected the amplitude of the heart contractions.

Effect of Various Xenobiotics on Hatching Success of Spodoptera exigua Eggs as Compared to a Natural Plant Extract

The effects of fenitrothion, carbaryl, and mancozeb, present in polluted water and plant extracted glycoalkaloids, were examined on hatching success of Spodoptera exigua eggs. All chemicals produced a significant decrease in hatching success, which was correlated with chemical concentration. One of the most interesting aspects of this study relates to the biological activity of glycoalkaloids.

Patterns in the distribution of avian lice (Phthiraptera: Amblycera, Ischnocera) living on the great grey shrike Lanius excubitor

The lice parasite community of great grey shrike Lanius excubitor collected in NE Slovakia during 1962–1974 was quantitatively studied. Lice fauna comprised of three species: Docophorulus coarctatus, Bruelia cruciata (Ischnocera) and Lanicanthus camelinus (Amblycera). All these species were previously indicated as characteristic for that host. The prevalence of lice was high—lice were recovered from 96.3% (n=108) host specimens. Distributions of lice on the great grey shrike, a strictly territorial bird, were aggregated, indicating substantial variation in the abundance of lice. Sex ratios of lice were biased towards females and not correlated with the subpopulation size of lice on individual hosts.

Effects of diflubenzuron and mancozeb on soil microarthropods: a long-term study

Effects of diflubenzuron and mancozeb on soil microarthropods: a long-term study Soil microarthropods exposed to the pesticides mancozeb (240 mg per 1 m2) or diflubenzuron (7.2 mg of diflubenzuron per 1 m2) were studied for 6 months after a single application. The observed taxa included Collembola, Insecta, Myriapoda, and 4 groups of mites: Actinedida (=Prostigmata), Gamasina, Uropodina, and Oribatida. Their abundance in soil was subject to seasonal fluctuations, but for a majority of taxa no significant differences were noticed between the control and exposed plots. The total number of microarthropods was insignificantly lower in exposed groups. Myriapods were the only taxon that was close to extinction after a single exposure to diflubenzuron. These data prove that soil has some buffering capacity, and this fact should always be taken into consideration when estimating the risk for the environment. However, the situation may change if the application of pesticides is repeated.

POTATO LEAF EXTRACT AND ITS COMPONENT, α‐SOLANINE, EXERT SIMILAR IMPACTS ON DEVELOPMENT AND OXIDATIVE STRESS IN Galleria mellonella L.

Plants synthesize a broad range of secondary metabolites that act as natural defenses against plant pathogens and herbivores. Among these, potato plants produce glycoalkaloids (GAs). In this study, we analyzed the effects of the dried extract of fresh potato leaves (EPL) on the biological parameters of the lepidopteran, Galleria mellonella (L.) and compared its activity to one of the main EPL components, the GA α-solanine. Wax moth larvae were reared from first instar on a diet supplemented with three concentrations of EPL or α-solanine. Both EPL and α-solanine affected survivorship, fecundity, and fertility of G. mellonella to approximately the same extent. We evaluated the effect of EPL and α-solanine on oxidative stress in midgut and fat body by measuring malondialdehyde (MDA) and protein carbonyl (PCO) contents, both biomarkers of oxidative damage. We evaluated glutathione S-transferase (GST) activity, a detoxifying enzyme acting in prevention of oxidative damage. EPL and α-solanine altered MDA and PCO concentrations and GST activity in fat body and midgut. We infer that the influence of EPL on G. mellonella is not enhanced by synergistic effects of the totality of potato leaf components compared to α-solanine alone.

Morphological diversity of pedicels in phoretic deutonymphs of Uropodina mites (Acari: Mesostigmata).

The pedicel is a structure that connects the phoretic deutonymph of Uropodina mites with its carrier and enables dispersal. The shapes, lengths and diameters of pedicels formed by Uropoda orbicularis, Trichouropoda ovalis, Uroobovella pulchella and Uroobovella nova were studied by scanning and light microscopy. Pedicels of U. orbicularis and T. ovalis have the shape of a straight stalk. In U. pulchella, the pedicel is extremely short, irregularly shaped and composed of homogeneous material. The longest pedicel is found in U. nova and it may be helically coiled in this species. The length of the pedicel is positively correlated with deutonymph body size between species, but not within species. Pedicels of U. orbicularis and U. pulchella have the largest diameter. The pedicel diameter in U. orbicularis and T. ovalis is inversely proportional to its length, but not in U. nova and U. pulchella. The constituent of pedicel stems in U. pulchella is homogeneous, whereas in U. orbicularis and T. ovalis it contains a bundle of tightly packed fibres. In U. nova coiled pedicels are comprised of two layered materials of different electron density, one of which is electron lucid and located peripherally. Hypotheses on the origin of the pedicel are proposed.