Sensitive detection of human growth hormone mRNA in routinely formalin-fixed,paraffin-embedded transgenic mouse tissues by non-isotopic in situ hybridization

A sensitive technique of non-isotopic in situ hybridization (NISH) is presented, which permits the detection of human growth hormone (hGH) mRNA in routinely formalin-fixed, paraffin-embedded transgenic mouse tissues and human post mortem pituitaries; the latter were used as positive tissue controls in this study. In addition, a double staining procedure combining NISH and immunohistochemistry for the visualization of both hGH and hGH mRNA in the same paraffin section is described. Digoxigenin-labelled antisense hGH RNA was used for NISH of hGH mRNA. The NISH protocol was based upon an established radioactive method. Alkaline phosphatase and horseradish peroxidase-based immunoenzymatic procedures for the detection of digoxigenin-labelled RNA probes using different chromogens [4-nitro blue tetrazolium chloride (NBT), Fast Blue BB, New Fuchsin, and 3,3-diaminobenzidine tetrahydrochloride (DAB) with or without intensification of the DAB staining] were compared. The proteolytic tissue pretreatment and the detection procedure were found to be the most critical steps for successful visualization of hGH mRNA. After optimization of the permeabilization conditions, hGH mRNA could be visualized in each case studied when alkaline phosphatase/NBT-based detection was employed. The NISH technique presented here, performed either separately or in combination with immunohistochemistry, permits retrospective analyses, of hGH (trans)gene expression in archival, paraffin-embedded specimens.     

NPY- and C-PON-immunoreactive substances in the central nervous system of Helix pomatia

The distribution of neuropeptide-tyrosin (NPY)- and C-flanking peptide of neuropeptide-tyrosine (C-PON)-immunoreactivities in the central nervous system of the pulmonate gastropod, Helix pomatia, was investigated. NPY- and C-PON-like substances were localized in neuronal somata and neuntes, but were not co-localized within the same cells. NPY-immunoreactive substances were also found in endocrine/paracrine like cells located in the epineurium. C-PON and NPY, both reduced serotonin activated isometric contractions of Helix aorta, suggesting that they may act as modulators in the control of the vascular system.     

Glutamate Dehydrogenase Is Not Essential for Glutamate Formation by Corynebacterium glutamicum

Two Corynebacterium glutamicum strains, one being glutamate dehydrogenase (GDH) negative and the other possessing 11-fold-higher specific GDH activity than the parental wild type, were constructed and used to analyze the role of GDH in C. glutamicum. The results indicate (i) that GDH is dispensable for glutamate synthesis required for growth and (ii) that although a high level of GDH increases the intracellular glutamate pool, the level of GDH has no influence on glutamate secretion.     

Formation of acetyl-CoA in Zymomonas mobilis by a pyruvate dehydrogenase complex

In the gram negative, obligately ethanologenic bacterium Zymomonas mobilis a pyruvate dehydrogenase complex was identified and the complex was enriched from cell extracts. This multienzyme complex is responsible for acetyl-CoA biosynthesis from pyruvate. No activities of related multienzyme complexes, 2-ketoglutarate dehydrogenase and branched chain keto acid dehydrogenase, could be detected.     

Two centuries of spatial and temporal dynamics of freshwater fish introductions

Aim

Investigating major freshwater fish flows (translocations) between biogeographic regions and their temporal dynamics and also quantifying spatial patterns and temporal changes in the array of introduced species, and the emergence and distance between major donor and recipient regions.

Location

Global.

Time Period

1800–2020.

Major Taxa Studied

Freshwater fishes.

Methods

We analysed a global dataset on freshwater fish introductions (4241 events of 688 species). Freshwater fish flows were investigated with flow diagrams and χ² tests, while PERMANOVA (permutational multivariate analysis of variance) was used to test the association between species and regions and temporal shifts. Cluster analysis revealed major recipient areas and composition of the introduced species. Finally, changes in distances between donor and recipient sites were tested with PERMANOVA.

Results

The number of introductions between biogeographic regions mirrored the European and North American dominance before World War II (WWII) and the trends in recreational fishing, biocontrol programmes and food production, especially in the Sino-Oriental region, which has a long tradition of aquaculture and fishkeeping. Over the years, the origins and composition of introduced species changed uniquely in each biogeographic region, although the most introduced species are common to every region. Salmonids and other cold-water species were frequently introduced before the 1950s, whereas tropical ornamental and aquaculture species currently prevail. Distances between donor and recipient sites did not vary over the time. After WWII, the Sino-Oriental region consolidated its dominance and the Ethiopian and Neotropical regions emerged as new global donor and recipient regions.

Main Conclusions

Global policy should focus on tropical ornamental and aquaculture species, which could benefit from global warming, especially in the Sino-Oriental region, because it currently dominates freshwater fish species flows, and the Ethiopian and Neotropical regions, because they recently emerged as important global donor and recipient regions of freshwater fish introductions.     

Identification of a UDP-glucosyltransferase conferring deoxynivalenol resistance in Aegilops tauschii and wheat

Aegilops tauschii is the diploid progenitor of the wheat D subgenome and a valuable resource for wheat breeding, yet, genetic analysis of resistance against Fusarium head blight (FHB) and the major Fusarium mycotoxin deoxynivalenol (DON) is lacking. We treated a panel of 147 Ae. tauschii accessions with either Fusarium graminearum spores or DON solution and recorded the associated disease spread or toxin-induced bleaching. A k-mer-based association mapping pipeline dissected the genetic basis of resistance and identified candidate genes. After DON infiltration nine accessions revealed severe bleaching symptoms concomitant with lower conversion rates of DON into the non-toxic DON-3-O-glucoside. We identified the gene AET5Gv20385300 on chromosome 5D encoding a uridine diphosphate (UDP)-glucosyltransferase (UGT) as the causal variant and the mutant allele resulting in a truncated protein was only found in the nine susceptible accessions. This UGT is also polymorphic in hexaploid wheat and when expressed in Saccharomyces cerevisiae only the full-length gene conferred resistance against DON. Analysing the D subgenome helped to elucidate the genetic control of FHB resistance and identified a UGT involved in DON detoxification in Ae. tauschii and hexaploid wheat. This resistance mechanism is highly conserved since the UGT is orthologous to the barley UGT HvUGT13248 indicating descent from a common ancestor of wheat and barley.     

Über die Einwirkung Hypotonischer Medien auf das Zwischenhirn-Hypophysensystem von Mugil und Gobius

Zusammenfassung Bei den Teleostiern Mugil und Gobius wurden die Veränderungen des Zwischenhirn-Hypophysensystems in veränderten Außenmedien (hypotonisches Seewasser) histologisch untersucht.Beim langsamen Überführen aus Seewasser von 38,4 S in Seewasser von 25,4 und 20,8 S nahm das Sekret nicht, wie erwartet, zu. Im Nucleus praeopticus und im Hinterlappen der Hypophyse erfolgt eine starke Verringerung des Sekretbestandes (Mugil). Erst in Seewasser von weit niedrigerem Salzgehalt (6,3 und 1, 4) nimmt das Sekret im Hypophysenhinterlappen wieder zu (Gobius). Bei 6 S ist eine intensive Sekretableitung im N.p. und Tractus praeopticohypophyseus zu beobachten. Eine Deutung der Ergebnisse wird versucht, indem das weitgehend konstante Innenmedium mit den wechselnden Außenfaktoren in Beziehung gebracht wird.Die Befunde weisen darauf hin, daß das Zwischenhirn-Hypophysensystem auch bei Teleostiern an der Regulation des Wasserhaushaltes beteiligt ist.Der Deutschen Forschungsgemeinschaft danke ich für die Gewährung eines Stipendiums, das mir den Aufenthalt in Neapel ermöglichte. Mein besonderer Dank gilt auch den Herren Prof. Dr. Remane, Prof. Dr. Bargmann und Dozent Dr. Schiebler für ihre Unterstützung.     

Untersuchungenüber Das tageszeitlich gebundene Schlüpfen yon Pseudosmittia Arenaria (Dipt. Chironomidae)

Zusammenfassung In einleitenden terminologischen Erwägungen wird vorgeschlagen, den Ausdruck Schlüpfrhythmus zugunsten von tageszeitlich gebundenem Schlüpfen aufzugeben. Pseudosmittia arenaria zeigt im normalen Tag-Nachtwechsel ein deutliches tageszeitlich gebundenes Schlüpfen mit einem Maximum 6–8h nach DL (Beginn der Beleuchtung).In Dauerdunkel schlüpfen keine Imagines. In Dauerlicht erscheinen die Tiere gleichmäßig über den ganzen Tag verteilt.Der ganze Bereich des sichtbaren Lichtes (geprüft von 476–641 m) ist wirksam. Auch die Lichtintensität in Licht-Dunkelbedingungen spielt im untersuchten Bereich (18–350 Lux) keine Rolle.Das Schlüpfmaximum von Ps. arenaria zeigt eine deutliche Beziehung zu DL. Es wandert bei konstanter Tageslänge um so dichter an DL heran, je kürzer die relative Länge der Lichtzeit ist.Bei kürzeren Tageslängen wandert das Maximum von DL fort, bei längeren an DL heran. Bei Tagen, die kürzer als 18h sind, liegt es in der folgenden Dunkelzeit, bei solchen, die länger als 36h sind, vor DL. Sein Weg beschreibt dabei eine kubische Parabel.Beim Eintritt des Gipfels in die folgende Dunkelzeit erscheint ein Maximum nur an jedem 2. Tag. Ein Maximum vor DL ruft ein zusätzliches Maximum in der gleichen Entfernung von LD (Beginn der Dunkelzeit) hervor. Bei extremen Tageslängen ist also dennoch ein Maximum ungefähr alle 24h zu beobachten. Dies ist exogen bedingt. Verlagert man durch schwache Beleuchtung während der Dunkelzeit das Maximum im 12h-Tag in die Lichtzeit, so erhält man ein Maximum an jedem Tag. Der Eintritt des Maximums in eine Dunkelzeit hat also das Umspringen auf einen Schlüpfgipfel an jedem 2. Tag bzw. auf 2 je Tag zur Folge.Im 12h-Tag mit absoluter Dunkelzeit während der Dunkelzeit kann man auch ein Maximum alle 12h erreichen, und zwar durch Umstimmung eines Teils der Population. Man hat dann 2 Gruppen, deren Maxima um 12h gegeneinander verschoben sind. Hemmend und fördernd auf den Einfluß des Lichtes wirken Temperatur und Substratfeuchtigkeit. Beide Faktoren können ohne Licht kein Schlüpfen hervorrufen. Beziehungen zwischen Lebensweise, Ökologie oder systematischer Stellung und tageszeitlich gebundenem Schlüpfen lassen sich bisher nicht feststellen.     

First report on new evidence for the occurrence of Podocarpus and possible human presence at the mouth of the Amazon during the Late-glacial

Palynological studies on late Quaternary lake sediments from the region of the Amazon estuary, 100 km north-east of Belém, Pará State, Brazil, enable reconstruction of lowland Amazonian rain forest during the Late-glacial and Holocene periods. Late-glacial forests included populations of Podocarpus which suggests a distinct climatic cooling. Ilex was abundant in the early Holocene. Records of the mangrove taxon, Rhizophora, indicate rapid Atlantic sea-level rise in the beginning of the Holocene. High charcoal representation may reflect the first arrival of Amerindians in the Amazon coastal area, probably about 10 800 B.P.