Entomofauna van Meinweg en Roerdal - verslag van de 157e zomerbijeenkomst te Herkenbosch

Deze bijdrage vormt een bundeling van de entomologische waarnemingen gedaan door de deelnemers aan de 157e zomerbijeenkomst van de NEV, welke plaatsvond van 31 mei tot 2 juni 2002 te Herkenbosch, Midden-Limburg. Er werden 1174 taxa geregistreerd van zes ordes. Met 793 taxa namen de kevers ongeveer tweederde van de soorten voor hun rekening. Opvallend hoog was de wantsenrijkdom: er werden 170 soorten gevangen. Het aantal nieuwe soorten voor de provincie Limburg was zeer beperkt. Limburg is dan ook van oudsher en voor alle insectengroepen de best onderzochte provincie. De waterkever Chaetarthria similis, de trips Odontothrips ignobilis en de mijt Anthoseius richteri worden hier voor het eerst van ons land gemel

Entomofauna van Noordoost-Twente verslag van de 158e zomerbijeenkomst te Ootmarsum

De 158e zomerbijeenkomst van de NEV vond plaats van 13 tot 15 juni 2003 in de provincie Overijssel in de omgeving van Ootmarsum. Deze bijdrage vormt de neerslag van de inventarisatieactiviteiten die door de deelnemers aan dit weekend werden ontplooid. Er werden 1484 taxa geregistreerd behorend tot negentien verschillende ordes van geleedpotigen. Met 744 taxa namen de kevers ongeveer de helft van de soorten voor hun rekening. Het aantal nieuwe soorten voor de provincie Overijssel was beperkt. Hoewel Overijssel van oudsher een relatief goed onderzochte provincie is, leverde de uitgebreide terreininventarisaties een schat aan (deels nieuwe) entomologische gegevens op. De roofmijten Anthoseius piceae en Typhlodromus bichaetae werden voor het eerst in Nederland waargenome

Het genus Melanophthalma (Coleoptera: Latridiidae) in Nederland

Dwergschimmelkevers (Melanophthalma curticollis en M. suturalis) zijn niet gemakkelijk te onderscheiden. Aandacht voor determinatie, verspreiding, fenologie en biotoop van beide soorte

Gene-expression profiling of White spot syndrome virus in vivo

White spot syndrome virus, type species of the genus Whispovirus in the family Nimaviridae, is a large, double-stranded DNA (dsDNA) virus that infects crustaceans. The genome of the completely sequenced isolate WSSV-TH encodes 184 putative open reading frames (ORFs), the functions of which are largely unknown. To study the transcription of these ORFs, a DNA microarray was constructed, containing probes corresponding to nearly all putative WSSV-TH ORFs. Transcripts of 79 % of these ORFs could be detected in the gills of WSSV-infected shrimp (Penaeus monodon). Clustering of the transcription profiles of the individual genes during infection showed two major classes of genes: the first class reached maximal expression at 20 h post-infection (p.i.) (putative early) and the other class at 2 days p.i. (putative late). Nearly all major and minor structural virion-protein genes clustered in the latter group. These data provide evidence that, similar to other large, dsDNA viruses, the WSSV genes at large are expressed in a coordinated and cascaded fashion. Furthermore, the transcriptomes of the WSSV isolates WSSV-TH and TH-96-II, which have differential virulence, were compared at 2 days p.i. The TH-96-II genome encodes 10 ORFs that are not present in WSSV-TH, of which at least seven were expressed in P. monodon as well as in crayfish (Astacus leptodactylus), suggesting a functional but not essential role for these genes during infection. Expression levels of most other ORFs shared by both isolates were similar. Evaluation of transcription profiles by using a genome-wide approach provides a better understanding of WSSV transcription regulation and a new tool to study WSSV gene functio

Comparison of micro-array profiling in senescing iris and carnation flowers

Gene expression profiles of cut Iris and carnation flowers were studied using cDNA microarrays. The cDNA libraries were enriched for flower-specific genes by subtraction with cDNA from subtending growing tissue. This strategy is meant to eliminate most household genes and numerous genes that are not specific for petals and senescence. In Iris, we spotted about 1400 clones and in carnation about 2000, of which 220 and 90 clones respectively were (partially) sequenced. Unexpectedly, during Iris senescence up-regulation was observed for many genes that previously had been characterized as being defence-related. Although such genes were also found in carnation, their relative contribution to the changes in expression seemed less pronounced. Another remarkable result was the limited number of known ethylene-related genes in carnation that were detected. Among those found was ACO1. Other ethylene-related genes may have been lost in the subtraction; and ACO1 seems specific for the ethylene climacteric. No ethylene-related genes were found in Iris. Since ethylene does not regulate petal senescence in Iris this is no surprise. Some similarities were found between Iris and carnation. In both species a considerable proportion of the up-regulated genes encode enzymes that are involved in the degradation of lipids, protein, and complex carbohydrates such as cell walls. Several genes involved in signal transduction and in transcription were observed to change expression levels in both species, but none were the same in both species, as judged from the limited sequence information. A novel EIN3 (EIL) transcription factor was discovered in carnation. The expression pattern of some putative transcription factors in carnation were expressed independently of ethylene treatment, and may be candidates for early regulators of traits such as ethylene senstivity. The detailed results on Iris have been published in the December 2003 issue of Plant Molecular Biology (53: 845-865); the results on carnation have been submitted

A non-directed approach to the differential analysis of multiple LC-MS-derived metabolic profiles

An essential element of any strategy for non-targeted metabolomics analysis of complex biological extracts is the capacity to perform comparisons between large numbers of samples. As the most widely used technologies are all based on mass spectrometry (e.g. GCMS, LCMS), this entails that we must be able to compare reliably and (semi)automatically large series of chromatographic mass spectra from which compositional differences are to be extracted in a statistically justifiable manner. In this paper we describe a novel approach for the extraction of relevant information from multiple full-scan metabolic profiles derived from LC–MS analyses. Specifically-designed software has made it possible to combine all mass peaks on the basis of retention time and m/z values only, without prior identification, to produce a data matrix output which can then be used for multivariate statistical analysis. To demonstrate the capacity of this approach, aqueous methanol extracts from potato tuber tissues of eight contrasting genotypes, harvested at two developmental stages have been used. Our results showed that it is possible to discover reproducibly discriminatory mass peaks related both to the genetic origin of the material as well as the developmental stage at which it was harvested. In addition the limitations of the approach are explored by a careful evaluation of the alignment quality

Verslag van de 159e zomerbijeenkomst te Den Hoorn

Tijdens de 159e zomervergadering van de NEV, die plaatsvond op Texel van 4 tot 6 juni 2004, zijn 1117 taxa van veertien insectenordes waargenomen. Hoewel ook dit keer wat aantal soorten betreft, kevers de boventoon voerden zijn er geen nieuwe keversoorten voor de provincie Noord-Holland gevonden. Met soortenlijst en lijst van vindplaatse

Entomofauna van Meinweg en Roerdal - verslag van de 157e zomerbijeenkomst te Herkenbosch

Deze bijdrage vormt een bundeling van de entomologische waarnemingen gedaan door de deelnemers aan de 157e zomerbijeenkomst van de NEV, welke plaatsvond van 31 mei tot 2 juni 2002 te Herkenbosch, Midden-Limburg. Er werden 1174 taxa geregistreerd van zes ordes. Met 793 taxa namen de kevers ongeveer tweederde van de soorten voor hun rekening. Opvallend hoog was de wantsenrijkdom: er werden 170 soorten gevangen. Het aantal nieuwe soorten voor de provincie Limburg was zeer beperkt. Limburg is dan ook van oudsher en voor alle insectengroepen de best onderzochte provincie. De waterkever Chaetarthria similis, de trips Odontothrips ignobilis en de mijt Anthoseius richteri worden hier voor het eerst van ons land gemel