Phylogenetic relationships of Microdontinae (Diptera: Syrphidae) based on molecular and morphological characters

The intrasubfamilial classification of Microdontinae Rondani (Diptera: Syrphidae) has been a challenge: until recently more than 300 out of more than 400 valid species names were classified in Microdon Meigen. We present phylogenetic analyses of molecular and morphological characters (both separate and combined) of Microdontinae. The morphological dataset contains 174 characters, scored for 189 taxa (9 outgroup), representing all 43 presently recognized genera and several subgenera and species groups. The molecular dataset, representing 90 ingroup species of 28 genera, comprises sequences of five partitions in total from the mitochondrial gene COI and the nuclear ribosomal genes 18S and 28S. We test the sister‐group relationship of Spheginobaccha with the other Microdontinae, attempt to elucidate phylogenetic relationships within the Microdontinae and discuss uncertainties in the classification of Microdontinae. Trees based on molecular characters alone are poorly resolved, but combined data are better resolved. Support for many deeper nodes is low, and placement of such nodes differs between parsimony and Bayesian analyses. However, Spheginobaccha is recovered as highly supported sister group in both. Both analyses agree on the early branching of Mixogaster, Schizoceratomyia, Afromicrodon and Paramicrodon. The taxonomical rank in relation to the other Syrphidae is discussed briefly. An additional analysis based on morphological characters only, including all 189 taxa, used implied weighting. A range of weighting strengths (k‐values) is applied, chosen such that values of character fit of the resulting trees are divided into regular intervals. Results of this analysis are used for discussing the phylogenetic relationships of genera unrepresented in the molecular dataset.     

Nogo/RTN4 isoforms and RTN3 expression protect SH-SY5Y cells against multiple death insults

Among the members of the reticulon (RTN) family, Nogo-A/RTN4A, a prominent myelin-associated neurite growth inhibitory protein, and RTN3 are highly expressed in neurons. However, neuronal cell-autonomous functions of Nogo-A, as well as other members of the RTN family, are unclear. We show here that SH-SY5Y neuroblastoma cells stably over-expressing either two of the three major isoforms of Nogo/RTN4 (Nogo-A and Nogo-B) or a major isoform of RTN3 were protected against cell death induced by a battery of apoptosis-inducing agents (including serum deprivation, staurosporine, etoposide, and H₂O₂) compared to vector-transfected control cells. Nogo-A, -B, and RTN3 are particularly effective in terms of protection against H₂O₂-induced increase in intracellular reactive oxygen species levels and ensuing apoptotic and autophagic cell death. Expression of these RTNs upregulated basal levels of Bax, activated Bax, and activated caspase 3, but did not exhibit an enhanced ER stress response. The protective effect of RTNs is also not dependent on classical survival-promoting signaling pathways such as Akt and Erk kinase pathways. Neuron-enriched Nogo-A/Rtn4A and RTN3 may, therefore, exert a protective effect on neuronal cells against death stimuli, and elevation of their levels during injury may have a cell-autonomous survival-promoting function.     

Impact of cranberry juice on initial adhesion of the EPS producing bacterium Burkholderia cepacia

The impact of cranberry juice was investigated with respect to the initial adhesion of three isogenic strains of the bacterium Burkholderia cepacia with different extracellular polymeric substance (EPS) producing capacities, viz. a wild-type cepacian EPS producer PC184 and its mutant strains PC184rml with reduced EPS production and PC184bceK with a deficiency in EPS production. Adhesion experiments conducted in a parallel-plate flow chamber demonstrated that, in the absence of cranberry juice, strain PC184 had a significantly higher adhesive capacity compared to the mutant strains. In the presence of cranberry juice, the adhesive capacity of the EPS-producing strain PC184 was largely reduced, while cranberry juice had little impact on the adhesion behavior of either mutant strain. Thermodynamic modeling supported the results from adhesion experiments. Surface force apparatus (SFA) and scanning electron microscope (SEM) studies demonstrated a strong association between cranberry juice components and bacterial EPS. It was concluded that cranberry juice components could impact bacterial initial adhesion by adhering to the EPS and impairing the adhesive capacity of the cells, which provides an insight into the development of novel treatment strategies to block the biofilm formation associated with bacterial infection.     

Evolutionary patterns–tested with cladistics–and processes in relation to palaeoenvironments of the Upper Barremian genus Gassendiceras (Ammonitina,Lower Cretaceous)

Abstract: Phylogenetic reconstruction of the Upper Barremian ammonite genus Gassendiceras (Gassendiceratinae) was performed using a cladistic analysis incorporating continuous data. Some morphological features were found to vary identically among all the analysed species and therefore carry no phylogenetic information (= symplesiomorphic). The single obtained cladogram allows interpreting the evolution of the Gassendiceras as an anagenetic succession of eight species, in stratigraphic order of appearance, Gassendiceras multicostatum, G. alpinum, G. hoheneggeri, G. rebouleti, G. bosellii, G. quelquejeui, G. coulletae and G. enayi. The clade Pseudoshasticrioceras/Imerites is derived from G. enayi, so the genus Gassendiceras appears to be paraphyletic. But here, we accept this fact as the best evolutive classification. The evolution over time of Gassendiceras is modulated by some processes, which could have constrained the inferred phylogenetic pattern with the drift of the global variability towards the most gracile forms over time. It is tempting to interpret this evolution as a constant selection over time of the Gassendiceras modulated by environmental control due to eustatic variation across a transgressive sequence. Thus, the most peramorphic (gracile) individuals seemed favoured at the expense of those most robust (paedomorphic).     

Effect of fruit maturity on UV-B-induced post-harvest anthocyanin accumulation in red Chinese sand pear

The effect of fruit maturity on UV-B-induced post-harvest anthocyanin accumulation in red Chinese sand pear (Pyrus pyrifolia Nakai) cultivar ‘Mantianhong’ was evaluated. During the irradiation, compared with the fruit harvested at 20 days before harvest (DBH) and 10 DBH, the mature fruit (harvested at commercial harvest date) had higher soluble solids content, soluble sugars concentration but lower firmness and starch content. In addition, higher content of anthocyanin has been detected in mature fruits than in immature fruits due to the significant increase in the expression of genes related to anthocyanin biosynthesis, especially PpCHS, PpF3H, PpANS, PpUFGT, PyMYB10 and PpbHLH in red Chinese sand pears. Hierarchical clustering analysis suggested that most genes related to anthocyanin biosynthesis showed a coordinate expression pattern. These findings are helpful in understanding the molecular mechanism of anthocyanin biosynthesis and regulation, which could lead to the development of new technologies for improving fruit color in Chinese sand pears and other fruits.     

Source Apportionment of Trace Element Pollution in Surface Sediments Using Positive Matrix Factorization Combined Support Vector Machines: Application to the Jinjiang River, China

In this study, a method of positive matrix factorization (PMF) combined support vector machines (SVMs) was adopted to identify possible sources and apportion contributions for trace element pollution in surface sediments from the Jinjiang River, Southeastern China. Utilizing diagnostics tools, four significant factors were extracted from sediment samplers, which were collected in December 2010 at 15 different sites. By treating source identification as a pattern recognition problem, the factor loadings derived from PMF were classified by SVM classifiers which have been trained and validated with fingerprints of eight potential source categories. Using SVM, industrial wastewater from lead ore mining and metal handcraft manufacture, atmospheric deposition, and natural background were identified as main sources of trace element pollution in surface sediments from the Jinjiang River, which were affirmed by visually comparing compound patterns and the differences between the predicted and actual fractional compositions. Apportionment results showed that source of lead ore mining made the largest contribution (33.62 %), followed by atmospheric deposition (30.99 %), metal handcraft manufacture (30.09 %), and natural background (5.29 %).     

S‐nitrosylated protein disulfide isomerase contributes to mutant SOD1 aggregates in amyotrophic lateral sclerosis

A major hallmark of mutant superoxide dismutase (SOD1)‐linked familial amyotrophic lateral sclerosis is SOD1‐immunopositive inclusions found within motor neurons. The mechanism by which SOD1 becomes aggregated, however, remains unclear. In this study, we aimed to investigate the role of nitrosative stress and S‐nitrosylation of protein disulfide isomerase (PDI) in the formation of SOD1 aggregates. Our data show that with disease progression inducible nitric oxide synthase (iNOS) was up‐regulated, which generated high levels of nitric oxide (NO) and subsequently induced S‐nitrosylation of PDI in the spinal cord of mutant SOD1 transgenic mice. This was further confirmed by in vitro observation that treating SH‐SY5Y cells with NO donor S‐nitrosocysteine triggered a dose‐dependent formation of S‐nitrosylated PDI. When mutant SOD1 was over‐expressed in SH‐SY5Y cells, the iNOS expression was up‐regulated, and NO generation was consequently increased. Furthermore, both S‐nitrosylation of PDI and the formation of mutant SOD1 aggregates were detected in the cells expressing mutant SOD1^G93A. Blocking NO generation with the NOS inhibitor N‐nitro‐l ‐arginine attenuated the S‐nitrosylation of PDI and inhibited the formation of mutant SOD1 aggregates. We conclude that NO‐mediated S‐nitrosylation of PDI is a contributing factor to the accumulation of mutant SOD1 aggregates in amyotrophic lateral sclerosis.     

Molecular cloning and characterization of the mitogen-activated protein kinase kinase gene (MKK4) and its promoter sequence from oilseed rape (Brassica campestris L.)

Mitogen-activated protein kinase (MAPK) cascades are involved in various processes, including plant growth and development as well as biotic and abiotic stress responses. MAPK kinases (MKKs), which link MPKs and MAPKK kinases (MKKKs), are crucial in MAPK cascades because these kinases mediate various stress responses in plants. However, only few MKKs in Brassica campestris (rape) have been functionally characterized. In this study, a novel gene, MKK4 that belongs to a C MKK group, was isolated and characterized from rape. Bioinformatics analysis revealed that the length of cDNA was 1,317 bp with an open reading frame of 993 bp, which encodes a polypeptide containing 330 amino acids, including a putative signal peptide with 27 amino acid residues and a mature protein with 303 amino acids. The obtained MKK4 exhibited a predicted molecular mass of 36.5 kDa and an isoelectric point of 9.01. Quantitative real-time polymerase chain reaction analysis revealed that MKK4 expression could be induced by cold and salt. We also found that the MKK4 protein is localized in the nucleus. In addition, a 999 bp promoter fragment of MKK4 was cloned. Sequence analysis revealed that several putative regulatory elements were found in the MKK4 promoter. Transient expression assay showed that the MKK4 promoter fragments exhibited promoter activity and stimulated GFP expression. The effects of GFP gene expression at different temperatures and in different onion epidermis culture patterns were compared. Results showed that the MKK4 promoter could respond to low temperature and salt stress. These results suggested that MKK4 is possibly important for the regulation of cold- and salt-stress responses in plants.