A cryptic invasion within an invasion and widespread introgression in the European water frog complex: consequences of uncontrolled commercial trade and weak international legislation

In Western Europe, many pond owners introduce amphibians for ornamental purposes. Although indigenous amphibians are legally protected in most European countries, retailers are circumventing national and international legislation by selling exotic nonprotected sibling species. We investigated to what extent non‐native species of the European water frog complex (genus Pelophylax) have become established in Belgium, using morphological, mitochondrial and nuclear genetic markers. A survey of 87 sampling sites showed the presence of non‐native water frogs at 47 locations, mostly Marsh frogs (Pelophylax ridibundus). Surprisingly, at least 19% of all these locations also harboured individuals with mitochondrial haplotypes characteristic of Anatolian water frogs (Pelophylax cf. bedriagae). Nuclear genotyping indicated widespread hybridization and introgression between P. ridibundus and P. cf. bedriagae. In addition, water frogs of Turkish origin obtained through a licensed retailer, also contained P. ridibundus and P. cf. bedriagae, with identical haplotypes to the wild Belgian populations. Although P. ridibundus might have invaded Belgium by natural range expansion from neighbouring countries, our results suggest that its invasion was at least partly enhanced by commercial trade, with origins as far as the Middle East. Also the invasion and rapid spread of Anatolian lineages, masked by their high morphological similarity to P. ridibundus, is likely the result of unregulated commercial trade. We expect that Anatolian frogs will further invade the exotic as well as the native range of P. ridibundus and other Pelophylax species elsewhere in Western and Central Europe, with risks of large‐scale hybridization and introgression.     

Ch-Schwellen der Uraninfärbbarkeit des Plasmas einiger Florideen

Ohne Zusammenfassung     

Osmotischer Druck und Ionengleichgewicht beim Blutegelmuskel

Zusammenfassung Es wurde das Verhalten des Blutegelrückenmuskels in Lösungen von verschiedenem osmotischen Druck und verschiedenem Ionengehalt untersucht. In reinen Zuckerlösungen sowie in reinen Kochsalzlösungen zeigt der Muskel einen von der Größe des osmotischen Druckes abhängigen Längszustand oder Tonus. Die Druck-Längenkurve zeigt in beiden Fällen einen Wendepunkt. Der in n/10-NaCl im Gleichgewicht befindliche Muskel erschlafft bei Herabsetzung des osmotischen Druckes bis zu einer Konzentration von n/20–n/30 und beginnt von da ab sich zu kontrahieren. In Na-freier Zuckerlösung liegt der Wendepunkt bei etwa molarer Konzentration, also bei etwa zehnmal so hohem osmotischen Druck. Erhöhung der Zuckerkonzentration führt zu Erschlaffung, Verminderung zu Kontraktion.Zusatz von Kalium zur NaCl-Lösung in einer die Isotonie nicht störenden Menge bewirkt eine wiederum von der Konzentration abhängige Längen- oder Tonusänderung, die gleichfalls einen Wendepunkt zeigt. Dieser liegt bei einer Konzentration von etwa n/250–n/200. Schwächere Konzentrationen bewirken eine Erschlaffung, stärkere eine Erhöhung des Muskeltonus. Kalzium wirkt in allen Konzentrationen erschlaffend. Es erscheint als Antagonist des Kaliums, wenn dieses kontrahierend wirkt, aber als Synergist, bei Kaliumkonzentrationen, die erschlaffend wirken.In O₂-reichem Medium bleibt die elektrische Reizbarkeit über 30 Stunden erhalten. Der Muskel zeigt ein großes Summationsvermögen, auch für einzeln unwirksame Reize. Die Erschlaffungsgeschwindigkeit steigt mit der Steilheit der Kontraktion. O₂-Mangel wirkt tonusvermindernd und erschlaffungsbeschleunigend. Hypotonie erhöht, Hypertonie vermindert die elektrische Reizbarkeit. Kalium hat wenig Einfluß, Kalzium erzeugt eine starke Herabsetzung der Reizbarkeit. Tonus und Reizkontraktion sind mithin von einander völlig unabhängige Erscheinungen.

---

Summary The behaviour of the dorsal muscle of leech in solutions of different osmotic pressure and different ions has been investigated. In pure sugar solutions as well as in pure solutions of sodium chloride the permanent state of length (tonus) of the muscle depends on the osmotic pressure of the solution. The curve representing the relation between pressure and length reveals in both cases a turning point. The muscle beeing in equilibrium in n/10-NaCl solution relaxes with diminishing osmotic pressure untill a concentration of n/20–n/30 is reached. With further diminution starts a contraction.In sodium free sugar solutions the turning point lies at approximatly molar concentrations that is at osmotic pressure ten times higher. Increase of sugar concentration leads to relaxation and its diminution to a contraction.Addition of potassium to the NaCl solution without disturbing the isotonic condition produces also a change of the state of length or the tonus. This change too depends on the concentration and shows a turning point at a K-concentration of about n/250–n/200. Lower concentrations produce a relaxation and higher ones a contraction. Calcium has a relaxing effect in all concentrations. It is an antagonist of potassium as far as the latter one produces a contraction, but acts as its Synergist in K-concentrations leading to a relaxation.In a medium rich in oxygen the electrical excitability of the muscle may be preserved for more than 30 hours. The muscle shows a great power of summation even for single shocks not effective by itself. The velocity of relaxation increases with the steepness of the contraction. Lack of oxygen diminishes the tonus and accelerates the relaxation. Hypotonic solutions increase while hypertonic ones diminish the electrical excitability. Potassium has little influence whereas calcium produces a strong diminution of excitability.Therefore tonus and contractions by stimulation are entirely independent phenomena.

---

---

Karl von Frisch zum 60. Geburtstag gewidmet.     

Polyploids and aneuploids of crepis capillaris produced by treatment with nitrous oxide

Summary When plants ofCrepis capillaris are treated with nitrous oxide of ten atmospheres pressure for four to six hours, at the time when the first or second zygotic divisions are passing in their pollinated flowers, a fair yield of polyploid and aneuploid plants is obtained in their progeny.     

Benthic resources are the key to Daphnia middendorffiana survival in a high arctic pond

1. Shallow arctic lakes and ponds have simple and short food webs, but large uncertainties remain about benthic–pelagic links in these systems. We tested whether organic matter of benthic origin supports zooplankton biomass in a pond in NE Greenland, using stable isotope analysis of carbon and nitrogen in the pond itself and in a ¹³C‐enrichment enclosure experiment. In the latter, we manipulated the carbon isotope signature of benthic algae to enhance its isotopic discrimination from other potential food sources for zooplankton. 2. The cladoceran Daphnia middendorffiana responded to the ¹³C‐enrichment of benthic mats with progressively increasing δ¹³C values, suggesting benthic feeding. Stable isotope analysis also pointed towards a negligible contribution of terrestrial carbon to the diet of D. middendorffiana. This agreed with the apparent dominance of autochthonous dissolved organic matter in the pond revealed by analysis of coloured dissolved organic matter. 3. Daily net production by phytoplankton in the pond (18 mg C m^?2 day^?1) could satisfy only up to half of the calculated minimum energy requirements of D. middendorffiana (35 mg C m^?2 day^?1), whereas benthic primary production alone (145 mg C m^?2 day^?1) was more than sufficient. 4. Our findings highlight benthic primary production as a major dietary source for D. middendorffiana in this system and suggest that benthic organic matter may play a key role in sustaining pelagic secondary production in such nutrient‐limited high arctic ponds.     

Gene flow and range expansion in a mountain‐dwelling passerine with a fragmented distribution

We studied gene flow and bottleneck events in the population history of locally isolated citril finches endemic to European mountains. For the present study, we used two genetic markers with different rates of evolution: a fast evolving mitochondrial marker (ATPase6/8) and a more slowly evolving nuclear marker (02401). Populations north of the Pyrenees showed in general fewer haplotypes and a considerable lower nucleotide and gene diversity than the Iberian populations. Unexpectedly, we found very little genetic variability in the fast evolving mitochondrial marker, arguing for a strong and relatively recent bottleneck event in the species population history. This pattern potentially reflects a sudden decrease of crucial resources during Mid‐Holocene (mountain pine, Scots pine, and black pine) and a subsequent breakdown of the population. The bottleneck could also have been caused or coincide with a selective sweep in the mitochondrion. By contrast, the slowly evolving nuclear marker showed a much higher variability. This marker probably reflects major gene flow along a potential expansion pathway from the Eastern Pyrenees, northwards to the populations of Central Europe, and southwards to the more fragmented populations of central and southern Spain. The population of the Western Pyrenees (Navarra) appears to be cut‐off from this major gene flow and our data indicate a certain degree of partial isolation, probably reflecting more ancient events (e.g. the separation in distinct refuge sites during the last glacial maximum). © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, 103 , 707–721.     

Cytotoxic and genotoxic effects of dioxacarb by human peripheral blood lymphocytes CAs and Allium test

Dioxacarb (Elecron, Famid) is a phenyl methylcarbamate insecticide and in vitro cytotoxic and genotoxic effects of this pesticide on human peripheral blood lymphocytes and Allium root meristematic cells were investigated by chromosomal aberrations (CAs) and Allium test. Human lymphocytes were treated with 62.5, 125, 250 and 500 ppm doses of dioxacarb for CAs. CA/cell, abnormal cell % and mitotic index % (MI %) data were obtained from these concentrations in 24 and 48 h treatment periods. Dioxacarb did not increase the CA/cell frequency significantly, so this insecticide was not identified as genotoxic. But it was found cytotoxic especially at 250 and 500 ppm concentrations because of the reduced the MI % and increased the abnormal cell %. In Allium test, 25 ppm (EC50/2), 50 ppm (EC50) and 100 ppm (EC50 × 2) concentrations were used for root growth inhibition (EC50 determination) and Allium mitotic index (MI) determination tests. The used concentrations of dioxacarb induced dose-dependent inhibition of MI and root growth on root meristems. Mitotic inhibition of dioxacarb was found significantly higher than for the positive control. These Allium results indicated the high cytotoxicity of dioxacarb. The present study is the first research on cytotoxicity and genotoxicity of dioxacarb by human lymphocyte CAs and Allium test.     

Impact of tannic acid on blood pressure,oxidative stress and urinary parameters in L-NNA-induced hypertensive rats

Hypertension is a major health problem with increasing prevalence around the world. Tannic acid is water-soluble polyphenol that is present in tea, green tea, coffee, red wine, nuts, fruits and many plant foods. It has been reported to serve as an antioxidant or a pro-oxidant depending on the type of cells and its concentration. The purpose of our study was to evaluate the effect of tannic acid on systolic blood pressure, oxidative stress and some urinary parameters in the rat model of essential hypertension. Blood pressures of all rats were measured using the tail-cuff method. The nitric oxide synthase inhibitor N (omega)-nitro-L-arginine was administered orally at a dose of 0.5 g/l/day for 15 days to rats in order to create an animal model of hypertension. Tannic acid was intraperitoneally injected at a dose of 50 mg/kg for 15 days. Superoxide dismutase, catalase activity and the concentration of malondialdehyde (MDA) were determined in blood plasma and homogenates of heart, liver and kidney. In order to evaluate renal functions, urine pH, urine volume, urine creatine, uric acid, and urea nitrogen values were measured. Compared with the hypertension group, a decrease in MDA concentrations of heart tissue (p < 0.01), urea nitrogen values (p < 0.01) and urine volumes (p < 0.001) were established in hypertension + tannic acid group. There was also a decrease in blood pressure values (20th and 30th days) of this group, but there was no a statistical difference according to hypertension group. The findings of our research show the effect of tannic acid in lowering blood pressure in hypertensive rats.     

Characterization of some bread wheat genotypes using molecular markers for drought tolerance

Because of its wide geographical adaptation and importance in human nutrition, wheat is one of the most important crops in the world. However, wheat yield has reduced due to drought stress posing threat to sustainability and world food security in agricultural production. The first stage of drought tolerant variety breeding occurs on the molecular and biochemical characterization and classification of wheat genotypes. The aim of the present study is characterization of widely grown bread wheat cultivars and breeding lines for drought tolerance so as to be adapted to different regions in Turkey. The genotypes were screened with molecular markers for the presence of QTLs mapped to different chromosomes. Results of the molecular studies identified and detected 15 polymorphic SSR markers which gave the clearest PCR bands among the control genotypes. At the end of the research, bread wheat genotypes which were classified for tolerance or sensitivity to drought and the genetic similarity within control varieties were determined by molecular markers. According to SSR based dendrogram, two main groups were obtained for drought tolerance. At end of the molecular screening with SSR primers, genetic similarity coefficients were obtained that ranged from 0.14 to 0.71. The ones numbered 8 and 11 were the closest genotypes to drought tolerant cultivar Gerek 79 and the furthest genotypes from this cultivar were number 16 and to drought sensitive cultivar Sultan 95. The genotypes as drought tolerance due to their SSR markers scores are expected to provide useful information for drought related molecular breeding studies.     

Body size but not colony size increases with altitude in the holarctic ant,Leptothorax acervorum

1. Bergmann's rule states that organisms inhabiting colder environments show an increase in body size or mass in comparison to their conspecifics living in warmer climates. Although originally proposed for homoeothermic vertebrates, this rule was later extended to ectotherms. In social insects, only a few studies have tested this rule and the results were ambiguous. Here, ‘body size’ can be considered at two different levels (the size of the individual workers or the size of the colony). 2. In this study, data from 53 nests collected along altitudinal gradients in the Alps were used to test the hypotheses that the worker body size and colony size of the ant Leptothorax acervorum increase with increasing altitude and therefore follow Bergmann's rule. 3. The results show that the body size of workers but not the colony size increases with altitude. Whether this pattern is driven by starvation resistance or other mechanisms remains to be investigated.