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.     

Der histochemische Nachweis von Schwefelsäure-Estern mit Trypaflavin

Zusammenfassung Es werden zwei Methoden zum histochemischen Nachweis von Schwefelsäureestern mitgeteilt, die beide auf der Verwendung von Trypaflavin beruhen. Einmal wird der Farbstoff als einfaches Fluorochrom verwendet, die Schwefelsäureester sind dabei durch ihre orange-gelbe Fluoreszenzmetachromasie erkennbar (Methode I). Das andere Verfahren bietet die Möglichkeit, das bereits angelagerte Fluorochrom mit p-Dimethylaminobenzaldehyd zu einem rot gefärbtem Komplex umzusetzen (Methode II). Färbungsvorgang, Spezifität und Haltbarkeit wurden näher untersucht.Anwendung zum Nachweis von Cerebrosidsch wefelsäureester-Ablagerungen, Mastzellengranula und, nach vorausgegangener Sulfatierung, zur elektiven Pilzdarstellung.Mit 11 Textabbildungen, davon 5 farbigen     

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.

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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.

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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.     

Biotization of Arabidopsis thaliana with Pseudomonas putida and assessment of its positive effect on in vitro growth

Determination of the optimal inoculation method and concentration to use for plant-bacteria interaction studies is important in many cases, such as the phytoremediation of heavy metals and other toxic compounds in contaminated areas. The aim of this study was to compare different concentrations and times of inoculation of Pseudomonas putida with various growth stages of Arabidopsis thaliana in 14-d in vitro cultures. A significant beneficial impact of the bacterium was detected in the shoot length and root weight of seedlings. The highest shoot length and root fresh and dry weights were detected in 14-d and 2 × 10³ cfu mL⁻¹ inoculated samples. In addition, the increase in root weight could be visualized with crystal violet staining, as relatively more root hair and lateral root formation occurred in seedlings inoculated with moderate concentrations of bacteria, possibly due to the ability of P. putida to produce indole-acetic acid. Moreover, the highest photosynthetic pigment accumulation was obtained with the highest bacterial inoculum (2 × 10⁶ cfu mL⁻¹), which was tested in 0- or 3-d-old seedlings. Rhizospheric bacterial colonization was also visualized with GFP-labeled bacteria by confocal microscopy. These results showed that biotization of A. thaliana with P. putida KT2440 did not cause severe oxidative stress in seedlings, because H₂O₂ accumulation levels together with CAT and POX activities were not significantly induced. Therefore, this strain could be used for several applications based on plant-bacteria interactions.

     

Chloroplasts require glutathione reductase to balance reactive oxygen species and maintain efficient photosynthesis

Thiol‐based redox‐regulation is vital for coordinating chloroplast functions depending on illumination and has been throroughly investigated for thioredoxin‐dependent processes. In parallel, glutathione reductase (GR) maintains a highly reduced glutathione pool, enabling glutathione‐mediated redox buffering. Yet, how the redox cascades of the thioredoxin and glutathione redox machineries integrate metabolic regulation and detoxification of reactive oxygen species remains largely unresolved because null mutants of plastid/mitochondrial GR are embryo‐lethal in Arabidopsis thaliana. To investigate whether maintaining a highly reducing stromal glutathione redox potential (E_GSH) via GR is necessary for functional photosynthesis and plant growth, we created knockout lines of the homologous enzyme in the model moss Physcomitrella patens. In these viable mutant lines, we found decreasing photosynthetic performance and plant growth with increasing light intensities, whereas ascorbate and zeaxanthin/antheraxanthin levels were elevated. By in vivo monitoring stromal E_GSH dynamics, we show that stromal E_GSH is highly reducing in wild‐type and clearly responsive to light, whereas an absence of GR leads to a partial glutathione oxidation, which is not rescued by light. By metabolic labelling, we reveal changing protein abundances in the GR knockout plants, pinpointing the adjustment of chloroplast proteostasis and the induction of plastid protein repair and degradation machineries. Our results indicate that the plastid thioredoxin system is not a functional backup for the plastid glutathione redox systems, whereas GR plays a critical role in maintaining efficient photosynthesis.     

Identification of copy number variants in children and adolescents with autism spectrum disorder: a study from Turkey

Molecular Biology Reports - Copy number variants (CNVs) play a key role in the etiology of autism spectrum disorder (ASD). Therefore, recent guidelines recommend chromosomal microarrays (CMAs) as...