Territoriality in lizards

Teritorialita u ještěrů Jan Chmelař Abstrakt: Teritorialita je velmi často diskutovaný fenomén, který se vyskytuje u všech skupin obratlovců na intraspecifické úrovni. Ještěři mezi nimi přesto zaujímají prominentní pozici díky ohromné variabilitě teritoriálního chování mezi vyššími taxony, druhy, populacemi i jedinci. Příkladem mohou být systémy sociální dominance, teritorialita samic nebo teritorialita na interspecifické úrovni. Její význam z hlediska kontroly reprodukce a exkluzivity zdrojů je zjevný a zpravidla zvyšuje fitness jedinců, kteří si svá teritoria ohlídat dokáží. Zároveň však zvyšuje expozici jedince a jeho náchylnost k predaci, je velice energeticky náročná v neposlední řadě někdy komplikuje snahy konzervačních biologů tím, že u druhů v různém stupni ohrožení, snižuje genetickou variabilitu jednotlivých populací. Klíčová slova: teritorialita, sociální dominance, ještěři, domovský okrsekTerritoriality in lizads Jan Chmelař Abstract : Territoriality is a widely discussed phenomenon occuring among all groups of vertebrates on intraspecific level. Nevertheless, lizards occupy a prominent position due to a nearly endless variability in forms of territorial behaviour on the levels of higher taxons, species, populations and individuals. Examples could be systems of social dominance hierarchy, female territoriality or interspecific territoriality. Importance of territoriality is obvious as a way of reproduction control and exclusive usage of space and resources and has a positive impact on individuals that are able to defend their territories. On the other hand, there is a higher exposure to predators and a cost in a form of depleted energy. One other thing is that it sometimes complicates efforts of conservational biologists by lowering genetic variability inside populations of endangered species. Key words: territoriality, social dominance, lizards, home rangeKatedra zoologieDepartment of ZoologyPřírodovědecká fakultaFaculty of Scienc

Insight into the sialome of the castor bean tick, Ixodes ricinus

<p>Abstract</p> <p>Background</p> <p>In recent years, there have been several sialome projects revealing transcripts expressed in the salivary glands of ticks, which are important vectors of several human diseases. Here, we focused on the sialome of the European vector of Lyme disease, <it>Ixodes ricinus</it>.</p> <p>Results</p> <p>In the attempt to describe expressed genes and their dynamics throughout the feeding period, we constructed cDNA libraries from four different feeding stages of <it>Ixodes ricinus </it>females: unfed, 24 hours after attachment, four (partially fed) and seven days (fully engorged) after attachment. Approximately 600 randomly selected clones from each cDNA library were sequenced and analyzed. From a total 2304 sequenced clones, 1881 sequences forming 1274 clusters underwent subsequent functional analysis using customized bioinformatics software. Clusters were sorted according to their predicted function and quantitative comparison among the four libraries was made. We found several groups of over-expressed genes associated with feeding that posses a secretion signal and may be involved in tick attachment, feeding or evading the host immune system. Many transcripts clustered into families of related genes with stage-specific expression. Comparison to <it>Ixodes scapularis </it>and <it>I. pacificus </it>transcripts was made.</p> <p>Conclusion</p> <p>In addition to a large number of homologues of the known transcripts, we obtained several novel predicted protein sequences. Our work contributes to the growing list of proteins associated with tick feeding and sheds more light on the dynamics of the gene expression during tick feeding. Additionally, our results corroborate previous evidence of gene duplication in the evolution of ticks.</p

Ixodes ricinus Salivary Serpin Iripin-8 Inhibits the Intrinsic Pathway of Coagulation and Complement.

Tick saliva is a rich source of antihemostatic, anti-inflammatory, and immunomodulatory molecules that actively help the tick to finish its blood meal. Moreover, these molecules facilitate the transmission of tick-borne pathogens. Here we present the functional and structural characterization of Iripin-8, a salivary serpin from the tick Ixodes ricinus, a European vector of tick-borne encephalitis and Lyme disease. Iripin-8 displayed blood-meal-induced mRNA expression that peaked in nymphs and the salivary glands of adult females. Iripin-8 inhibited multiple proteases involved in blood coagulation and blocked the intrinsic and common pathways of the coagulation cascade in vitro. Moreover, Iripin-8 inhibited erythrocyte lysis by complement, and Iripin-8 knockdown by RNA interference in tick nymphs delayed the feeding time. Finally, we resolved the crystal structure of Iripin-8 at 1.89 Å resolution to reveal an unusually long and rigid reactive center loop that is conserved in several tick species. The P1 Arg residue is held in place distant from the serpin body by a conserved poly-Pro element on the P' side. Several PEG molecules bind to Iripin-8, including one in a deep cavity, perhaps indicating the presence of a small-molecule binding site. This is the first crystal structure of a tick serpin in the native state, and Iripin-8 is a tick serpin with a conserved reactive center loop that possesses antihemostatic activity that may mediate interference with host innate immunity

Protecting isolated reptile populations outside their main area of distribution: a predictive model of the Dice snake, Natrix tessellata, distribution in the Czech Republic

Marginal populations of animals are highly susceptible to environmental pressures associated with climatic changes. Understanding their distribution and ecological requirements is, thus, essential for the development of efficient conservation strategies. The dice snake, Natrix tessellata, is listed as critically endangered in the Czech Republic. In certain regions (Bohemia and Silesia), its populations are located beyond the northern border of the continuous range of the species, while the south Moravian populations are connected to it. Based on the statewide database of the Czech Nature Conservation Agency, we created a predictive model and determined key factors influencing the species distribution. The most relevant factors were: watercourses and bodies, average annual temperatures, altitude, slope inclination and precipitation seasonality. The model fits the presence records well and is applicable in both theory and practice of the species conservation – for example, focusing faunistic research to certain areas, critical analysis of controversial presence reports and as an input for species management in the form of repatriation and introduction

Iripin-1, a new anti-inflammatory tick serpin, inhibits leukocyte recruitment in vivo while altering the levels of chemokines and adhesion molecules

Serpins are widely distributed and functionally diverse inhibitors of serine proteases. Ticks secrete serpins with anti-coagulation, anti-inflammatory, and immunomodulatory activities via their saliva into the feeding cavity to modulate host’s hemostatic and immune reaction initiated by the insertion of tick’s mouthparts into skin. The suppression of the host’s immune response not only allows ticks to feed on a host for several days but also creates favorable conditions for the transmission of tick-borne pathogens. Herein we present the functional and structural characterization of Iripin-1 (Ixodes ricinus serpin-1), whose expression was detected in the salivary glands of the tick Ixodes ricinus, a European vector of tick-borne encephalitis and Lyme disease. Of 16 selected serine proteases, Iripin-1 inhibited primarily trypsin and further exhibited weaker inhibitory activity against kallikrein, matriptase, and plasmin. In the mouse model of acute peritonitis, Iripin-1 enhanced the production of the anti-inflammatory cytokine IL-10 and chemokines involved in neutrophil and monocyte recruitment, including MCP-1/CCL2, a potent histamine-releasing factor. Despite increased chemokine levels, the migration of neutrophils and monocytes to inflamed peritoneal cavities was significantly attenuated following Iripin-1 administration. Based on the results of in vitro experiments, immune cell recruitment might be inhibited due to Iripin-1-mediated reduction of the expression of chemokine receptors in neutrophils and adhesion molecules in endothelial cells. Decreased activity of serine proteases in the presence of Iripin-1 could further impede cell migration to the site of inflammation. Finally, we determined the tertiary structure of native Iripin-1 at 2.10 Å resolution by employing the X-ray crystallography technique. In conclusion, our data indicate that Iripin-1 facilitates I. ricinus feeding by attenuating the host’s inflammatory response at the tick attachment site

Addendum: Kotál et al. Ixodes ricinus Salivary Serpin Iripin-8 Inhibits the Intrinsic Pathway of Coagulation and Complement. Int. J. Mol. Sci. 2021, 22, 9480

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Innate immunity based cancer immunotherapy: B16-F10 murine melanoma model

Abstract Background Using killed microorganisms or their parts to stimulate immunity for cancer treatment dates back to the end of 19th century. Since then, it undergone considerable development. Our novel approach binds ligands to the tumor cell surface, which stimulates tumor phagocytosis. The therapeutic effect is further amplified by simultaneous application of agonists of Toll-like receptors. We searched for ligands that induce both a strong therapeutic effect and are safe for humans. Methods B16-F10 murine melanoma model was used. For the stimulation of phagocytosis, mannan or N-formyl-methionyl-leucyl-phenylalanine, was covalently bound to tumor cells or attached using hydrophobic anchor. The following agonists of Toll-like receptors were studied: monophosphoryl lipid A (MPLA), imiquimod (R-837), resiquimod (R-848), poly(I:C), and heat killed Listeria monocytogenes. Results R-848 proved to be the most suitable Toll-like receptor agonist for our novel immunotherapeutic approach. In combination with covalently bound mannan, R-848 significantly reduced tumor growth. Adding poly(I:C) and L. monocytogenes resulted in complete recovery in 83% of mice and in their protection from the re-transplantation of melanoma cells. Conclusion An efficient cancer treatment results from the combination of Toll-like receptor agonists and phagocytosis stimulating ligands bound to the tumor cells.http://deepblue.lib.umich.edu/bitstream/2027.42/134739/1/12885_2016_Article_2982.pd

Territoriality in lizards

Territoriality in lizads Jan Chmelař Abstract : Territoriality is a widely discussed phenomenon occuring among all groups of vertebrates on intraspecific level. Nevertheless, lizards occupy a prominent position due to a nearly endless variability in forms of territorial behaviour on the levels of higher taxons, species, populations and individuals. Examples could be systems of social dominance hierarchy, female territoriality or interspecific territoriality. Importance of territoriality is obvious as a way of reproduction control and exclusive usage of space and resources and has a positive impact on individuals that are able to defend their territories. On the other hand, there is a higher exposure to predators and a cost in a form of depleted energy. One other thing is that it sometimes complicates efforts of conservational biologists by lowering genetic variability inside populations of endangered species. Key words: territoriality, social dominance, lizards, home rang

Ecology,ethology and variability of european green lizard Lacerta viridis in Natural reservation Tiché údolí

The european green lizard, Lacerta viridis is a critically endangered reptile species which is in the region of Bohemia present only in relict isolated populations. These populations are closely linked to slopes with a southern exposition in deeply engorged river valleys. These valleys exhibit a unique climatic effect also known as the river phenomenon which allows numerous animal and plant species to survive far beyond their standard northern range. The chosen locality in Tiché údolí is a subject to long-term conservational management and the studied lizard population seems to reflect its effectiveness. This study is aimed to evaluate variability, ecological and ethological characteristics of lizards within the locality and is focused on changes on the population level. Key words: European green lizard, Lacerta viridis, Tiché údolí, river phenomenon, variability, ecology, ethology, population characteristics Abstrakt Ještěrka zelená, Lacerta viridis, je kriticky ohrožený druh plaza, který se na území Čech vyskytuje pouze v reliktních a izolovaných populacích. Ty jsou úzce spjaty se svahy v hluboko zaříznutých říčních údolích. Tato údolí vykazují unikátní klimatický efekt, známý též jako říční fenomén, který umožňuje výskyt četných živočišných i rostlinných druhů i za severní hranicí jejich běžného..