FOLIA BIOLOGICA-KRAKOW

Early Development and Post Embryonic Skeletal Morphology of the Progeny of Spined Loach Cobitis taenia L. (Teleostei, Cobitidae) and its Naturally Occurring Allotriploids
Juchno D, Boron A, Szlachciak J and Kujawa R
Polyploid fishes of the genus Cobitis represent a valuable model system to study the origin and consequences of hybridization and polyploidization within vertebrates. These naturally accessible polyploids are an excellent subject to determine the advantages or disadvantages of polyploidy. We investigated the embryonic and larval development with skeletal morphology of diploid and polyploid Cobitis progeny, obtained from crosses between females and males of Cobitis taenia and between allotriploid Cobitis females and C. taenia males. Observations were made during first fourteen days post fertilization. The pattern of development of all investigated individuals was the same. However the diploids developed synchronically, achieving successive stages faster than the polyploid ones; hatching was observed at 50 and 63 hours post fertilization, respectively. Statistically significant differences in hatching success and survival rate between diploid and polyploid progeny were not observed. All newly hatched larvae were characterized by a large amount of yolk, forty myomeres, body pigmentation and four external gills. Skeletal elements of the chondrocranium in the first days post hatching consisted of the otic capsule, ethmoid plate, trabeculae cranii and Meckel's cartilage. In contrast to the diploids, the polyploid larvae were characterized by a higher number of deformities. This study gives new comparative data on the features of early development of diploid and polyploid Cobitis progeny.
Expression of Caveolin-1 in Human Cutaneous and Uveal Melanoma Cells
Belkot K, Bubka M and Litynska A
Caveolin-1 can act as a tumour promoter or suppressor depending on the cancer type and stage. In melanoma, information available concerning its expression is ambiguous. In this study, we investigated caveolin-1 mRNA and protein expression levels in human melanoma cell lines of different origin and progression stages. Metastatic cutaneous (WM-266-4, A375), primary cutaneous (WM- 115, IGR-39) and primary uveal (mel-202, 92-1) cells were used for quantitative RT-PCR, Western blotting and confocal microscopy. We observed significantly higher expression of caveolin-I mRNA in cutaneous than in uveal melanoma cells. In accordance, immunostaining of caveolin-I was stronger in cutaneous cell extracts, while protein bands of uveal origin displayed weak signals. Finally, we detected differences in the caveolin-I subcellular pattern of distribution between primary and metastatic cells. Overall, this is the first demonstration of caveolin-1 expression in human primary uveal melanoma cell lines and observation that the origin of cells (uveal/cutaneous) has an impact when considering the utility of caveolin-I as a melanoma cell marker.
Immunolocalization of the TASK2 Potassium Channel in Frog Kidney
Nesovic-Ostojic J, Markovic-Lipkovski J, Todorovic J, Cirovic S, Kovacevic S, Paunovic A, Cemerikic D and Milovanovic A
TASK2 (K2P5. 1, KCNK5) is a two-pore domain K⁺ channel belonging to the TALK subgroup of the K2P family of proteins. TASK2 expression has been reported in a variety of cells and tissues ranging from kidney to immune cells and including specific neurons, its proposed functions spanning from involvement in the regulation of cell volume to control of excitability. The purpose of this study was to determine the tubule location ofthe TASK2 K⁺ channel protein in frog kidney applying polyclonal antibody against the carboxyl terminus of human TASK2 (KCNK5) protein. Immunohistochemical analysis revealed that TASK2 is expressed on distal tubules and proximal epithelial cells. TASK2 is strongly expressed predominantly on the luminal part ofthe proximal epithelial cells and slightly cytoplasmatic staining is expressed. Distal tubules showed diffuse cytoplasmatic staining as well as slight staining on the apical parts ofthe cells. These findings suggest that the TASK2 K⁺ channel has cell-specific roles in renal potassium ion transport.
Functional Morphology of the Upper and Lower Eyelids, Third Eyelid, Lacrimal Gland and Superficial Gland of the Third Eyelid in the Red Kangaroo (Macropus rufus)
Kleckowska-Nawrot J, Gozdziewska-Harlajczuk K, Barszcz K and Janeczek M
A study concerning the upper (UE) and lower (LE) eyelids, lacrimal gland (LG), superficial gland of the third eyelid (SGTE) and third eyelid (TE) was conducted on 4 sexually mature red kangaroos (2 males and 2 females). Gross anatomical, histological, histometrical, histochemical and ultrastructural (TEM) components were compared. Tissue sections were stained with haematoxylin and eosin, azan-trichrome, van Gieson, Masson-Goldner trichrome, methyl green-pyronin Y, periodic acid-Schiff, alcian blue pH 2.5, aldehyde fuchsin and Hale's dialysed iron. The location of the LG, SGTE, TE, UE and LE was similar to that of other mammals. Organized lymphoid follicles were also found in the LE. The TE resembled the letter T and was composed of cartilage (hyaline tissue). The LG was relatively larger than the SGTE. The LG and SGTE were multilobar tubuloacinar glands. The LG had more plasma cells than the SGTE. The SGTE and LG secretions were mucoserous in composition. The TEM study showed that the secretory cells of the LG and SGTE have a similar ultrastructural appearance. Two types of secretory vesicles were detected in the cytoplasm in acini and one type of secretory vesicle was found in the tubules of these glands.
Seasonal Variability of the Paramecium aurelia Complex in the Botanical Garden of the Jagiellonian University, Krak6w - in the Light of Species Composition and COI Haplotype Variation
Przybos E, Surmacz M and Tarcz S
The temporal occurrence of some Paramecium aurelia species is still an intriguing problem as cysts were never reported to exist in the Paramecium genus. A sequence of species occurrence was studied (by strain crosses and molecular identification) in five water-bodies of the Jagiellonian University Botanical Garden in Krak6w in different sampling sites and different seasons of the year. In the current study 20 P. aurelia strains were isolated from collected water samples and identified as P. biaurelia, P. tetraurelia, P. sexaurelia (the first record in Poland), P. novaurelia (the first record in the Botanical Garden). Generally only one species was found in the particular water body in a single sampling point in a given season - an exception was observed in the case of some strains of P. tetraurelia and P. sexaurelia. The latter species were mostly isolated from two water bodies situated in the Palm Houses (higher temperature preference) and P. biaurelia with P. novaurelia from water bodies located outside (lower temperature preference). Sequencing of the COImtDNA fragment revealed 9 haplotypes in the studied area which were characteristic for particular species. The most variable species was P. sexaurelia - 8 strains studied and 3 haplotypes identified. In contrast, P. novaurelia has only one haplotype for 6 strains collected in different seasons. The present study supports the hypothesis that botanical garden water bodies may be a hot-spot for microbial eukaryotic species-such as Paramecium.
The Evolutionary Relationships between Endosymbiotic Green Algae of Paramecium bursaria Syngens Originating from Different Geographical Locations
Zagata P, Greczek-Stachura M, Tarcz S and Rautian M
Paramecium bursaria (Ehrenberg 1831), a freshwater ciliate, typically harbors hundreds of green algal symbionts inside the cell. The aim of present study was the molecular identification of newly analyzed P. bursaria symbionts. The second aspect of the present survey was testing a hypothesis whether endosymbionts prefer the specified syngen of the host, and the specified geographical distribution. Ten strains of endosymbionts isolated from strains of P. bursaria originating from different geographical locations were studied. We analyzed for the first time, both the fragment of plastid genome containing 3'rpl36-5' infA genes and a fragment of a nuclear gene encoding large subunit ribosomal RNA (LSU rDNA). The analysis of the LSU rDNA sequences showed the existence of 3 haplotypes and the haplotype diversity of 0.733, and 8 haplotypes for the 3'rpl36-5' infA gene fragment and haplotype diversity of 0.956. The endosymbionts isolated from P. bursaria strains were identified as Chlorella vulgaris, Ch. variabilis and Micractinium conductrix. There was no correlation between the syngen of P. bursaria and the species of endosymbiont.
In Memoriam Professor Halina Kościuszko (1934-2015)
Prajer M
Exposure of Eisenia andrei (Oligochaeta; Lumbricidea) to Cadmium Polluted Soil Inhibits Earthworm Maturation and Reproduction but not Restoration of Experimentally Depleted Coelomocytes or Regeneration of Amputated Segments
Takacs V, Molnar L, Klimek B, Galuszka A, Morgan AJ and Plytycz B
Lumbricid earthworms are often exposed to polluted soil. They are also commonly subjected to various stimuli and attacks by predators that induce extrusion of coelomocyte-containing coelomic fluid and/or the loss of body segments followed by the renewal of immune-competent cells and regeneration of tissues/organs. The aim of our investigations was to test the effects of exposure of the earthworm Eisenia andrei to cadmium-polluted soil, combined with electrostimulation-induced depletion of coelomocytes (i.e. amoebocytes and chloragocyte-derived eleocytes) or the surgical amputation of posterior segments, on earthworm maturation, reproductive output, and regenerative processes. Experimental worms were maintained up to 7 weeks either in unpolluted soil or in soil spiked with cadmium chloride (500 mg/kg air-dried soil). In juvenile worms, sexual maturation (measured by clitellum formation) was delayed and cocoon production was inhibited in Cd-exposed worms. Coelomocytes were significantly depleted by electrostimulation and the kinetics of their recovery was similar in worms kept in clean and cadmium polluted soils, in both exposure conditions amoebocyte recovery was faster than recovery of riboflavin-storing eleocytes. In adult worms, soil cadmium exposure inhibited reproduction but, at macroanatomical level, had a negligible effect on regeneration of amputated posterior segments, visible only on histological cross-sections.
Histological Aspects of the Early Development of the Digestive System of Burbot Lota lota L. (Lotidae, Gadiformes)
Furgała-Selezniow G, Jankun M, Kujawa R, Nowosad J, Biłas M, Kucharczyk D and Skrzypczak A
The ontogeny of the digestive tract was studied histologically in burbot, Lota lota L., from hatching to 42 days post-hatch (dph). At hatching, the digestive tract consisted of a straight tube with discernible digestive accessory glands (the liver and the pancreas) dorsally attached to the yolk sac. Most of the yolk sac reserves were consumed during the first 12 days and were completely depleted by 17 dph. The first PAS-positive goblet cells appeared at 6 dph, dispersed within the epithelium of the oesophagus and increasing substantially in number and distribution as development progressed. At 12 dph, the first vacuoles (neutral lipids) appeared in the intestine, indicating the functional absorption of nutrients from food. Differentiation of gastric glands was first noticed at 17 dph and was extensive by 27 dph. L. lota larvae have a morphologically complete digestive tract by 32 dph. These findings on the development of the digestive system in L. lota may contribute to a better understanding of its ontogeny and can be useful for improvement of the larval rearing techniques of this promising species for freshwater aquaculture diversification.
n-3 and n-6 Fatty Acid Changes in the Erythrocyte Membranes of Patients with 658240251 Clostridium difficile Infection
Czepiel J, Gdula-Argasińska J and Garlicki A
The implications of circulating essential fatty acids (FA) on the inflammatory risk profile and clinical outcome are still unclear. In order to gain a deeper understanding of the role of polyunsaturated fatty acids (PUFA) in the pathogenesis of acute infection, we analyzed the FA content in red blood cell (RBC) membranes of patients with Clostridium difficile infection (CDI) and controls. We prospectively studied 60 patients including 30 patients with CDI and 30 controls to assess lipid concentrations in erythrocyte membranes using gas chromatography. We observed a higher level of saturated fatty acids (SFA) in RBC membranes from patients with CDI. In patients with CDI, we also noticed a higher level of 20:4 n-6 FA and only a small amounts of C20:2n-6, C20:3n-6 FAs, arachidonic acid (AA) precursors, which suggest an intense inflammatory reaction in the organism during infection. We also noticed low levels of n-3 FA in the RBC membranes of patients infected with CDI. There is a deficit of n-3 FA in patients with CDI. n-3 FA are probably used during CDI as precursors of pro-resolving mediators that may indicate a therapeutic role of n-3 PUFAs in CDI. The changes in fatty acids in erythrocyte membranes during CDI alter their functions which may have an impact on the clinical outcome.
Identification and Characterization of Pathogen-Response Genes (repat) in Spodoptera frugiperda (Lepidoptera: Noctuidae)
Machado V, Serrano J and Galián J
The fall armyworm (Spodoptera frugiperda, Noctuidae, Lepidoptera) is one of the most important crop pests in the Americas, causing significant damage to maize, rice and sorghum. The mechanisms that determine its defences against pathogens are particularly relevant for the development of management and control strategies. We used an in silico approach to identify and characterize pathogen response genes (repat) present in different tissue libraries of S. fugiperda. The analyses revealed complete cDNA for nine repat genes; of these, repat15 and repat39 were found in libraries from a specific tissue--the midgut of larvae fed with xenobiotic substances. High expression levels of some genes were found in different libraries: 39 hits in repat30 in challenged hemocytes, 16 hits in repat31 in fat body, 10 hits in repat32 in fat body and 10 in challenged hemocytes, and 10 hits in repat38 in midgut of non-treated larvae and midgut of larvae fed with natural and xenobiotic substances. The genes corresponded to two ontology categories, stress response and immune response, and their phylogenetic relationships, nucleotide similarity, number of amino acid residues and molecular weights agree with what has been described for repat genes. It is noteworthy that proteins encoded by the repat genes of S. frugiperda have important defence functions in other tissues beyond midgut and that their functional categories are likely diverse, as they are related to cell envelope structure, energy metabolism, transport and binding.
In Vitro Study of Caecal and Colon Microbial Fermentation Patterns in Wild Boar (Sus scrofa scrofa)
Pecka-Kiełb E, Bujok J, Miśta D, Króliczewska B, Górecka J and Zawadzki W
The aim of this study was to evaluate wild boar (Sus scrofa scrofa) caecal and colon products of microbial activity including short chain fatty acids (SCFA), ammonia and methane concentrations. The in vitro method was applied to caecal and colon contents after 12 and 24-hour incubation with the substrate (wheat bran), or without any additive (control samples). The pH was also measured in each sample. In samples incubated with the substrate, a lower pH was noted as compared to the control (P < 0.001). In terms of the total SCFA concentration, the hindgut microbial fermentation pattern of wild boar was characterized by a high acetate level, followed by propionate and then butyrate at a ratio of 7:1.5:1. Substrate addition decreased acetate molar proportions (P < 0.001) and increased those of butyrate (P < 0.001) as well as propionate (P < 0.05). The total SCFA level in fresh, unincubated caecal samples (128 mmol/kg) was similar to that in the colon (111 mmol/kg). The ammonia concentrations were at the level of 0.8-1.5 mmol/kg of hindgut content and did not differ between the two investigated hindgut parts. Methanogenesis was also similar in the caecum and colon and after 24h was 2.69 mmol/kg and 2.27 for caecal colon control samples, respectively. The substrate increased total gas production and methane concentration (P < 0.001).
Efficient Source of Cells in Proximal Oviduct for Testing Non-Viral Expression Constructs in the Chicken Bioreactor Model and for Other in Vitro Studies
Stadnicka K, Bodnar M, Marszałek A, Bajek A, Drewa T, Płucienniczak G, Chojnacka-Puchta L, Cecuda-Adamczewska V, Dunisławska A and Bednarczyk M
This work shows the usefulness of chicken oviduct epithelial cells (COEC) in evaluating the efficacy of non-viral expression vectors carrying human therapeutic genes. Secondly, an efficient source of progenitor COEC for in vitro studies is described. Within the distal part of the oviduct, weak to moderate expression of a trans membrane glycoprotein (CD44) was observed. Single cells presenting only weak expression of CD44 were found in magnum sections. in vitro cultured oviduct cells originating from the distal oviduct were suitable for subculturing and showed a stable proliferation potential up to the 2nd passage. However, the pavimentous epithelial-like morphology of COEC was progressively lost over time and mainly a fibroblast-like monolayer was established in consecutive passages. Moreover, various commercial transfection agents including FuGENE6 and XtremeGENE9 DNA were used to optimize delivery of human interferon alfa-2a, (IFNα2a) a therapeutic protein gene under an ovalbumin promoter. The transfection efficiency of adherent COEC was estimated for up to 40% at a ratio of 6:1 of transfectant to pOVA5EIFN + GFP plasmid. Expression of IFNα2a was confirmed by western blotting in transformed COEC. In conclusion, the population of epithelial progenitor cells sourced from the distal oviduct can significantly contribute to in vitro culture of COEC, representing an efficient model to develop the production of avian bioreactors and other in vitro studies related to oviduct tissue.
Effects of Prebiotics and Synbiotics Delivered In Ovo on Broiler Small Intestine Histomorphology During the First Days After Hatching
Bogucka J, Dankowiakowska A, Elminowska-Wenda G, Sobolewska A, Szczerba A and Bednarczyk M
The objective of the study was to determine the effect of prebiotics and synbiotics administered in ovo on the 12th day of incubation, on the development of the intestinal villi and the number of goblet cells in the small intestine of broiler chickens on the Ist and the 4th days of life of chicks. Two prebiotics: inulin (PI) or Bi2tos (PB) and two synbiotics: inulin + L. lactis subsp. lactis (SI) or Bi2tos + L. lactis subsp. cremoris (SB) were injected in ovo on the 12th day of embryonic development. The control group of the embryos was injected with physiological saline (C). On the 1st day of life, an increase in the height of the villi in the jejunum was reported as a result of the injection of pre- and synbiotics, moreover an increase in the surface area of the villi in the jejunum and the duodenum in chicks from the SB group was also observed. A stimulatory effect of synbiotics on the morphology of the duodenum and thejejunum was also observed on the 4th dh day after hatching. Conversely, in the ileum, in the SB group, a reduction in the height of villi was found both on thse 1t and thte 4h days of life. In contrast, injection of inulin and synbiotic with the addition of inulin resulted in an increase in the number of goblet cells in the duodenum and the jejunum on thst 1" day of life, and caused a significant decrease on the 4th day after hatching.
Adipose Tissue Tumor Necrosis Factor-α. and Interleukin-6 Response to Glucocorticoid Treatment during Inflammation
Zubel-Lojek J, Oclon E, Latacz A and Pierzchala-Koziec K
The study was performed to examine the actions of glucocorticoids on cytokine (TNF-α and IL-6) concentrations in blood plasma, adipose tissue and cytokines gene expression during acute (streptozotocin, STZ treatment) and chronic inflammation (overweight) in Swiss mice. The experiment was carried out on 6-week-old animals divided into two groups: I - non-obese (fed with a commercial food) and II - overweight mice (fed with a high-fat diet). In each group mice were divided into 4 experimental subgroups: I - control, II - acute inflammation (STZ), III - treated with glucocorticoids (DEX), and IV - STZ with DEX. After injections the animals were decapitated, blood and white adipose tissue (WAT) was quickly removed and directed to measure the plasma levels, tissue concentrations and gene expression of the cytokines (TNF-α, IL-6). Three weeks of treatment with a high-fat diet resulted in increased body weight gain and plasma level of cytokines, whereas did not change TNF-c and IL-6 mRNA gene expression in control animals. STZ, administered once, changed the TNF-α & and IL-6 concentrations in a different manner according to the diet. The TNF-a and IL-6 actions in mice white adipose tissue are down-regulated after glucocorticoids treatment only in overweight animals. The obtained results suggest that glucocorticoids' effects on adipose tissue immune response, both in a pro- and an anti-inflammatory manner, depend on the nutritional status.
Changes in Biochemical Properties of the Blood in Winter Swimmers
Teleglow A, Marchewka J, Marchewka A and Kulpa J
The aim of the study was to investigate the effects of winter swimming on biochemical indicators of the blood. The subjects - winter swimmers - belonged to the Krakow Walrus Club "Kaloryfer" - "The Heater". The study group consisted of 11 men, aged 30-50 years, 'walrusing' throughout the whole season from November to March. Statistically significant changes throughout the 'walrusing' season were observed for the following biochemical parameters: a decrease in sodium (mmol/1), chloride (mmol/1), alpha-2 globulin(g/1), gamma globulin (g/1), IgG (g/1), and an increase in albumin (g/1), indicator A/G, IgA (g/l ), Herpes simplex virus IgM. Seasonal effort of winter swimmers has a positive influence on biochemical blood parameters.
Muscle Fibre Characteristics and Physico-Chemical Parameters of m. semimembranosus from Pulawska, Polish Large White and Pietrain Pigs
Wojtysiak D, Gorska M and Wojciechowska J
The aim of the study was to compare muscle fibre parameters and quality of m. seninembranosus in pigs. The experiment was conducted with 18 Pulawska pigs, 24 Polish Large White (PLW) pigs, and 24 Pietrain pigs slaughtered at 105 kg body weight. The results obtained indicate that the breed of pigs has a significant effect on both muscle fibre composition and vascularization. The muscles of Pulawska pigs are the most oxidative, as evidenced by the greatest number of capillaries and the highest percentage of type I and IIA fibres compared to the muscle of PLW and Pietrain pigs. In turn, the most glycolytic muscles (highest percentage of type IIB fibres, poorest vascularization as well as the greatest diameters of muscle fibres of all types under analysis) were noted in Pietrain pigs. Analysis of the physico-chemical parameters of the meat showed the lowest pH45, a* and IMF, as well as the highest L*, drip loss and shear force values in Pietrain pigs compared to Pulawska and PLW pigs. Significantly higher IMF, and a* values, as well as lower drip loss, shear force and L* values were observed in Pulawska pigs.
On the Generic Position of Polyommatus avinovi (Lepidoptera: Lycaenidae)
Shapoval N and Lukhtanov V
Polyommatus avinovi (Stshetkin, 1980), an enigmatic taxon from Tajikistan has been considered in the literature either as a member of the genus Polyonimatus, or a taxon belonging to the genus Rimisia. None of the conclusions on taxonomy and nomenclature of P. avinovi were supported by molecular or cytological data, therefore the problem of identity and phylogenetic position of this taxon has remained unsolved. Here we use the barcoding fragment of the COIgene as a molecular marker to demonstrate that none of these hypotheses are true. Phylogenetic analysis revealed P. avinovi to be strongly differentiated from both Polyommatus and Rimisia. Instead, it formed a separated, well supported monophyletic clade within the genus Afarsia Korb & Bolshakov, 2011. Thus, we propose the following new combinations for this butterfly: Afarsia avinovi comb. nov. and Afarsia avinovi dangara comb. nov.
Antioxidant Enzymes in Brain Cortex of Rats Exposed to Acute, Chronic and Combined Stress
Pejic S, Stojikjkovic V, Todorovic A, Gavrilovic L, Pavlovic I, Popovic N and Pajovic SB
The study deals with manganese superoxide dismutase, copper, zinc superoxide dismutase, and catalase activities in brain cortex of Wistar rats exposed to acute stress (immobilization or cold for 2 h), chronic stress (long-term isolation or long-term forced swimming for 21 days), or to combined chronic/acute stress. We observed that i) single episodes of acute stress by immobilization increased activity of both superoxide dismutases; ii) both types of chronic stresses significantly elevated activities of all examined enzymes; iii) chronic social isolation was a much stronger stressor than physical stress by swimming; iv) in animals pre-exposed to chronic isolation, additional stress by immobilization or cold significantly decreased previously elevated activities of all enzymes, while after chronic swimming, acute immobilization lowered only catalase activity. The obtained results indicate that stress conditions most probably altered the cell redox equilibrium, thus influencing the antioxidant response in brain cortex. Further investigation of neuronal prooxidant/antioxidant cellular conditions is needed to improve the prevention and treatment of various stress induced diseases.
First Description of supernumerary Chromosomes in Ictaluruspunctatus Rafinesque 1818 Reveals Active Ribosomal Genes in the B Complement
do Prado FD, Daniel SN, Penitente M, Hashimoto DT, Foresti F and Porto-Foresti F
The North American channel catfish Ictalurus punctatus Rafinesque 1818 is cultivated in the United States, Asia and Brazilian fish farms, and also utilized as a model species in aquaculture and genetic studies. In this work, cytogenetic analysis of . punctatus from Brazilian aquaculture revealed for the first time the presence of extra elements (supernumerary or B chromosomes) in this species. These elements were characterized as dot-like micro B chromosomes and were found in three individuals (varying from 0 to 1) and in one individual with higher incidence per cell (varying from 0 to 5; mean number of Bs per cell = 2.01). More specific cytogenetic techniques in this individual revealed 58 A chromosomes (standard complement) containing heterochromatic bands in the centromeric regions, a single Ag-NOR in a subtelocentric pair (also positive for 18S rDNA using the FISH technique) and multiple 5S rDNA clusters in three different subtelocentric chromosomes. Four B chromosomes were entirely Ag-NOR positive (also fully heterochromatic) and three presented 18S rDNA clusters by FISH. The occurrence of Ag-NOR and 18S ribosomal genes in both A and B chromosome complements may indicate an intraspecific origin for these extra chromosomes. Additionally, the terminal location of 18S ribosomal clusters in the Ag-NOR-bearing chromosomes and the presence of active NOR in the B chromosomes suggested that breakage events may be related to a possible recent origin of these extra elements. We suggest this data may be useful as cytogenetic information for future elucidation of the composition, origin and evolution of extra chromosomes in fishes.
The Effect of an Eextremely Low Frequency Magnetic Field on Larvae Production in the Parasite-Host System: Fasciola hepatica-Galba truncatula: a Preliminary Study
Kołodziejczyk L, Podraza W, Gonet B, Dzika E and Kosik-Bogacka DI
The aim of this study was to determine the effect of an extremely low-frequency magnetic field (ELFMF) on the production of liver fluke larvae in a parasite-host system: Fasciola hepatica--Galba truncatula. Both F. hepatica eggs and F. hepatica-infected snails were exposed to an ELFMF (50 Hz, 2.0 mT) for 14 days and 36 days, respectively. F. hepatica-infected snails were divided into 4 groups, 10 specimens each. The snails of groups I and II were infected with F. hepatica larvae--miracidia obtained from control cultures, while the snails of groups III and IV were infected with miracidia reared from eggs that had been incubated in an ELFMF. After infection, the snails of groups II and IV were placed in an ELFMF, while those of groups I (control) and III were housed outside the ELFMF. At 36 days post-infection (dpi) there were no statistically significant differences between the number of F. hepatica larvae--cercariae and metacercariae, obtained from G. truncatula snails in the control group (group I) and the snail groups exposed to ELFMF (groups II, III and IV). However, a statistically significant difference between the average number of F. hepatica larvae in snail groups III and IV may indicate that the duration of exposure to ELFMF, i.e. embryogenesis period vs. the entire larval development, played a role in the production of F. hepatica larvae, and resulted in a reduction of their number.