Plant genome editing in the European Union—to be or not to be—a GMO

New plant-breeding techniques have been boosting plant breeding, since only a few years but already first promising products are pushing to the market. In contrast to this, in many countries, the current Directives regulating genetically modified organisms have been established more than 25 years ago, especially in the European Union being based on clear differentiation between transgenic plants and conventional breeding. Therefore, the question arises if these Directives are suitable to face the new challenge of genetic engineering or if there is a need for updated regulations.     

Naphthoquinone glycosides for bioelectroanalytical enumeration of the faecal indicator Escherichia coli

Microbial water quality monitoring for the presence of faecal indicator bacteria (FIB) is a mandatory activity in many countries and is key in public health protection. Despite technological advances and a need for methodological improvements, chromogenic and fluorogenic enzymatic techniques remain the mainstays of water quality monitoring for both public health agencies and regulated utilities. We demonstrated that bioelectroanalytical approaches to FIB enumeration are possible and can be achieved using commercially available enzyme‐specific resorufin glycosides, although these are expensive, not widely available or designed for purpose. Following this, we designed two naphthoquinone glycosides which performed better, achieving Escherichia coli detection in the range 5.0 × 10² to 5.0 × 10⁵ CFU ml^?1 22–54% quicker than commercially available resorufin glycosides. The molecular design of the naphthoquinone glycosides requires fewer synthetic steps allowing them to be produced for as little as US$50 per kg. Tests with environmental samples demonstrated the low tendency for abiotic interference and that, despite specificity being maintained between β‐glucuronidase and β‐galactosidase, accurate enumeration of E. coli in environmental samples necessitates development of a selective medium. In comparison to a commercially available detection method, which has U.S. Environmental Protection Agency (EPA) approval, our approach performed better at high organism concentrations, detecting 500 organisms in 9 h compared with 13.5 h for the commercial method. Bioelectroanalytical detection is comparable to current approved methods and with further development could result in improved detection times. A recent trend for low‐cost open‐source hardware means that automated, potentiostatically controlled E. coli detection systems could be constructed for less than US$100 per channel.     

Locus- and Site-Specific DNA Methylation of 19 kDa Zein Genes in Maize

An interesting question in maize development is why only a single zein gene is highly expressed in each of the 19-kDa zein gene clusters (A and B types), z1A2-1 and z1B4, in the immature endosperm. For instance, epigenetic marks could provide a structural difference. Therefore, we investigated the DNA methylation of the arrays of gene copies in both promoter and gene body regions of leaf (non-expressing tissue as a control), normal endosperm, and cultured endosperm. Although we could show that expressed genes have much lower methylation levels in promoter regions than silent ones in both leaf and normal endosperm, there was surprisingly also a difference in the pattern of the z1A and z1B gene clusters. The expression of z1B gene is suppressed by increased DNA methylation and activated with reduced DNA methylation, whereas z1A gene expression is not. DNA methylation in gene coding regions is higher in leaf than in endosperm, whereas no significant difference is observed in gene bodies between expressed and non-expressed gene copies. A median CHG methylation (25–30%) appears to be optimal for gene expression. Moreover, tissue-cultured endosperm can reset the DNA methylation pattern and tissue-specific gene expression. These results reveal that DNA methylation changes of the 19-kDa zein genes is subject to plant development and tissue culture treatment, but varies in different chromosomal locations, indicating that DNA methylation changes do not apply to gene expression in a uniform fashion. Because tissue culture is used to produce transgenic plants, these studies provide new insights into variation of gene expression of integrated sequences.     

Specific effects on enzyme activities upon ditution of petroselinum hortense cell cultures into water.

Large increases in the specific activities of phenylalanine ammonia-lyase (EC 4.3.1.5) and p-coumarate:CoA ligase (EC 6.2.1.-) occurred within a few hours after dilution of cultured Petroselinum hortense cells into water. No significant changes in the total amount of extractable protein and in the activities of chalcone isomerase (EC 5.5.1.6) and glutamate dehydrogenase (EC 1.4.1.2) were observed under the same conditions. The time course for the change in phenylalanine ammonia-lyase activity included a lag period of 2–3 h, a peak about 13 h after the onset of induction, and a subsequent period of rapid decline. The inducible amount of enzyme activity was greatly dependent upon the degree of dilution of the cells into water. Simultaneous induction by dilution and irradiation of the cells with white, fluorescent light resulted in an increase in the phenylalanine ammonia-lyase level of activity which exceeded that calculated from the sum of the separately induced levels. Consecutive inductions, first by dilution and then 5 h later by irradiation, each required a lag period of 2–3 h. Actinomycin D or cycloheximide were inhibitors of the induction. While the total protein-synthesizing capacity in vitro was not significantly influenced by the dilution of cells, analysis of the labeled products on polyacrylamide gels demonstrated small but significant changes in the radioactivity profiles. The results are consistent with the hypothesis that dilution of the cells into water reduces the concentration of one or more compounds of cellular origin, thereby stimulating the rate of de novo synthesis of a limited number of proteins.     

The genetic mucolipidoses

Summary This review is an attempt to define a group of storage diseases which exhibit signs and symptoms of both the mucopolysaccharidoses and sphingolipidoses. Lacking some of the characteristics of the mucopolysaccharidoses while resembling to this group of thesaurismoses in other respects, these diseases frequently were described as Hurler variants.In Gm₁ gangliosidosis types I and II, Fucosidosis, Mannosidosis and in infantile Sulfatidosis with mucopolysacchariduria enzyme defects have been identified which are thought to be causally related to the diseases. In others the pathogenesis is unknown. They are tentatively named Mucolipidosis I, II and III.Supported by grants Wi 80 and Sp 63/2 of the Deutsche Forschungsgemeinschaft.     

Untersuchungen zur Isolierung und Identifizierung des Schreckstoffes aus der Haut der Elritze,Phoxinus phoxinus (L.) (Cyprinidae,Ostariophysi, Pisces)

Zusammenfassung Es wurde versucht, den Schreckstoff aus der Haut der Elritze,Phoxinus phoxinus (L.) (Cyprinidae), zu isolieren und zu identifizieren. Hierfür wurden die einzelnen Fraktionen im Verhaltensexperiment an Schwärmen des Malabarbärblings,Danio malabaricus (Jerdon) auf ihren Schreckstoffgehalt geprüft. Nach der dünnschichtchromatographischen Auftrennung der reinsten Fraktionen löste nur das Eluat von zwei stark fluoreszierenden Flecken die Schreckreaktion aus. Die Ergebnisse von Vergleichsuntersuchungen an zwei weiteren Species, nämlich dem Malabarbärbling (Cyprinidae) und dem SalmlerAlestes longipinnis (Günther) (Characidae), stimmten mit den an der Elritze gewonnenen Befunden völlig überein. Beim Schreckstoff handelt es sich sehr wahrscheinlich um ein Pterin. Isoxanthopterin wurde als Vergleichssubstanz getestet und löste ebenfalls die Schreckreaktion aus.

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On the isolation and identification of the alarm substance from the skin of the European minnow,Phoxinus phoxinus (L.) (cyprinidae, ostariophysi, pisces)

Summary The alarm substance from the skin of the European minnow,Phoxinus phoxinus (L.) (Cyprinidae), was isolated and identified. The amounts of alarm substance in various fractions of the skin were tested by means of behavioural experiments on schools of the giant danio,Danio malabaricus (Jerdon). From all thinlayer chromatograms tested, only two strongly fluorescent spots elicited the fright reaction. The results of comparative investigations on two other species, the giant danio (Cyprinidae) and the long-finned African tetraAlestes longipinnis (Günther) (Characidae), were in complete agreement with the results onPhoxinus. The results indicate that the alarm substance very probably is a pterin. Comparative tests with isoxanthopterin also elicited the fright reaction.

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Mit Unterstützung durch die Deutsche Forschungsgemeinschaft.     

The role of glucose on the enzymes involved in the release of mature spores of Chlorella fusca

An enzyme with carbohydrate-releasing activity (CRA) plays a key role in the release of the mature autospores of Chorella fusca Shihira et Krauss var. vacuolata SAG 211-8B. CRA liberates oligomeric carbohydrates from isolated sprorangia walls and furthermore splits p -nitrophenyl-β- d -fucopyranoside. Observations on mixotrophically cultivated C. fusca and on isolated CRA indicated that in vitro the β- d -fucosidase activity is inhibited by glucose. In vivo glucose induces the well-known gigantism of the algal cells by blocking sporulation, and this leads to the formation of giant sporangia containing up to 128 spores. Glucose and fucose were the only inhibitors of CRA isolated from the homogenate of C. fusca cells.     

Neurochemistry of GABAergic System in Cerebral Cortex Chronically Exposed to Bromide In Vivo

Neurochemical correlates of GABAergic synaptic transmission [binding, uptake, metabolism, and tissue content of gamma-aminobutyric acid (GABA)] were investigated in the cortex of rats that had been given 27 mM bromide in drinking water for periods of time ranging from 1 day to 1 month. No effect of bromide on any of the parameters was found and it is concluded that chronic administration of bromide has no profound effect on GABAergic inhibitory system in the rat cortex.