Non-indigenous fish in the northern branch of the central European invasion corridor

The assessment of risks associated with non-indigenous species implies a detailed knowledge of their taxonomical composition and distribution within a certain region. The northern branch of the central European ‘invasion corridor’—a series of canals connecting different watersheds—has formed an important migratory route for Ponto-Caspian fish (i.e. fish from the Black Sea, the Sea of Azov and the Caspian Sea). However, the current status of non-indigenous fish species in this region is very scarce. This article presents a comprehensive overview of recent distribution data of non-indigenous fish species in the northern branch of the central European invasion corridor. Here, extensive data are integrated based on studies performed during 2003–2014 comprising reliable published and unpublished records from the last 12 years. Altogether, ten non-indigenous fish species were currently found in the northern branch of the central European invasion corridor, constituting 19 % of its freshwater fish diversity. Three species, including the Prussian carp (Carassius gibelio), the round goby (Neogobius melanostomus), and the Chinese sleeper (Perccottus glenii), are considered invasive species. Eight species may potentially invade this region in the near future. A comparison of the history of non-indigenous fish species introduction in the inland waters of the northern branch and other countries of the central European invasion corridor revealed similar introduction trends. Potential expansion of non-indigenous fish species across the central European invasion corridor has international implications that require awareness, cooperation, and government support from each individual country. Disclosure of recently operating vectors for non-indigenous fish introductions within the central European invasion corridor will help predict and prevent their further spread and establishment in this region.     

ω-Aga-I: A presynaptic calcium channel antagonist from venom of the funnel web spider,Agelenopsis aperta

Spider venoms are proving to be important sources of specific ion channel toxins. Venom of Agelenopsis aperta, a funnel web spider, contains a class of polypeptide toxins which blocks neuromuscular synapses at nanomolar concentrations. Detailed physiological analyses of block caused by one of these toxins, ω-Aga-I show that it suppresses transmitter release at insect and frog neuromuscular junctions and blocks calcium spikes in insect neuronal cell bodies. ω-Aga-I may define a binding site on neuronal calcium channels which is common to both vertebrates and invertebrates.     

Imaging pancreatic beta-cells in the intact pancreas

We have developed a method to visualize fluorescent protein-labeled beta-cells in the intact pancreas through combined reflection and confocal imaging. This method provides a 3-D view of the beta-cells in situ. Imaging of the pancreas from mouse insulin I promoter (MIP)-green (GFP) and red fluorescent protein (RFP) transgenic mice shows that islets, beta-cell clusters, and single beta-cells are not evenly distributed but are aligned along the large blood vessels. We also observe the solitary beta-cells in both fetal and adult mice and along the pancreatic and common bile ducts. We have imaged the developing endocrine cells in the embryos using neurogenin-3 (Ngn3)-GFP mice crossed with MIP-RFP mice. The dual-color-coded pancreas from embryos (E15.5) shows a large number of green Ngn3-expressing proendocrine cells with a smaller number of red beta-cells. The imaging technique that we have developed, coupled with the transgenic mice in which beta-cells and beta-cell progenitors are labeled with different fluorescent proteins, will be useful for studying pancreatic development and function in normal and disease states.     

Mitochondrial COI and morphological specificity of the mealy aphids (Hyalopterus ssp.) collected from different?hosts in Europe (Hemiptera,Aphididae)

Forty three European population samples of mealy aphids from various winter and summer host plants were attributed to respective species of Hyalopterus by means of their partial sequences of mitochondrial COI gene. Used Hyalopterus samples emerged as monophyletic relative to outgroup and formed three major clades representing three host specific mealy aphid species in the Neighbor joining, Maximum parsimony, Maximum likelihood and Bayesian inference trees. Hyalopterus pruni and Hyalopterus persikonus emerged as a sister species, whilst Hyalopterus amygdali was located basally. Samples representing different clades in the molecular trees were used for canonical discrimination analysis based on twenty two morphological characters. Length of the median dorsal head hair enabled a 97.3 % separation of Hyalopterus amygdali from the remaining two species. No single character enabled satisfactory discrimination between apterous viviparous females of Hyalopterus pruni and Hyalopterus persikonus. A modified key for the morphological identification of Hyalopterus species is suggested and their taxonomic status discussed.     

Strongmen sport is associated with larger absolute heart size and impaired cardiac relaxation

This study was carried out to compare cardiac structure and function and blood lipids among Strongmen, sedentary controls, and marathoners. Echocardiography was performed, and endothelial function, blood lipids and maximal oxygen uptake were measured in 27 Caucasian adult men (8 Strongmen, 10 marathoners, 9 controls). Absolute cardiac size parameters such as left ventricular (LV) diameter and wall thickness of Strongmen were higher (p < 0.05), but relative (body surface area indexed) parameters were not different between controls and Strongmen. In Strongmen, the relative LV diameter (p < 0.05), wall thickness (p < 0.001), and LV mass index (p < 0.01) were lower than in marathoners. The absolute but not relative right ventricular diameter was larger in Strongmen as compared with controls, whereas all of the measured relative cardiac size parameters were higher in marathoners as opposed to in controls. The endothelial function and the ratio of wall thickness to chamber diameter were similar among the groups (p > 0.05). Maximal oxygen uptake of Strongmen was lower than in controls (p < 0.05) and marathoners (p < 0.001). Global diastolic LV function of Strongmen was impaired in comparison to controls (p < 0.05) and marathoners (p < 0.05). Plasma lipids were not different between Strongmen and sedentary controls, but in comparison to runners, Strongmen had higher low-density lipoprotein-cholesterol (p < 0.05) and lower high-density lipoprotein cholesterol (p < 0.01). Participation in Strongmen sport is associated with higher absolute but not relative cardiac size parameters, impaired myocardial relaxation, and low cardiorespiratory fitness. Therefore, Strongmen may demand greater attention as an extreme group of athletes with regard to cardiovascular risk.     

Inherited phenotype instability of inflorescence and floral organ development in homeotic barley double mutants and its specific modification by auxin inhibitors and 2,4-D

Background and Aims Barley (Hordeum vulgare) double mutants Hv-Hd/tw₂, formed by hybridization, are characterized by inherited phenotypic instability and by several new features, such as bract/leaf-like structures, long naked gaps in the spike, and a wide spectrum of variations in the basic and ectopic flowers, which are absent in single mutants. Several of these features resemble those of mutations in auxin distribution, and thus the aim of this study was to determine whether auxin imbalances are related to phenotypic variations and instability. The effects of auxin inhibitors and 2,4-D (2,4-dichlorophenoxyacetic acid) on variation in basic and ectopic flowers were therefore examined, together with the effects of 2,4-D on spike structure.Methods The character of phenotypic instability and the effects of auxin inhibitors and 2,4-D were compared in callus cultures and intact plants of single homeotic Hv-tw₂ and Hv-Hooded/Kap (in the BKn3 gene) mutants and alternative double mutant lines: offspring from individual plants in distal hybrid generations (F₉–F₁₀) that all had the same BKn3 allele as determined by DNA sequencing. For intact plants, two auxin inhibitors, 9-hydroxyfluorene-9-carboxylic acid (HFCA) and p-chlorophenoxyisobutyric acid (PCIB), were used.Key Results Callus growth and flower/spike structures of the Hv-tw₂ mutant differed in their responses to HFCA and PCIB. An increase in normal basic flowers after exposure to auxin inhibitors and a decrease in their frequencies caused by 2,4-D were observed, and there were also modifications in the spectra of ectopic flowers, especially those with sexual organs, but the effects depended on the genotype. Exposure to 2,4-D decreased the frequency of short gaps and lodicule transformations in Hv-tw₂ and of long naked gaps in double mutants.Conclusions The effects of auxin inhibitors and 2,4-D suggest that ectopic auxin maxima or deficiencies arise in various regions of the inflorescence/flower primordia. Based on the phenotypic instability observed, definite trends in the development of ectopic flower structures may be detected, from insignificant outgrowths on awns to flowers with sterile organs. Phenotypically unstable barley double mutants provide a highly promising genetic system for the investigation of gene expression modules and trend orders.