An AT-rich DNA component in the genomes of Chironomus thummi thummi and Chironomus thummi piger

A DNA fraction has been isolated from total Chironomus thummi thummi DNA which is discernible from the bulk Ch. th. thummi DNA by a lower thermal stability. In situ hybridizations with polytene salivary gland chromosomes of Ch. th. thummi and Ch. th. piger made localization of this DNA fraction possible. Hybridizations with bands which contain different amounts of DNA in the two subspecies indicate that the isolated DNA fraction mostly consists of those sequences which represent the genetical difference between thummi and piger.This paper is dedicated to Professor Dr. H. Bauer on the occasion of his 75th birthday     

An autoradiographic analysis of hypothalamic magnocellular neurons

Summary A light and electron microscopic autoradiographic analysis revealed that H³-valine infused into the lateral ventricle of normal and acutely dehydrated cats is preferentially taken up by the supraoptic (SON) and paraventricular nucleus (PVN) of the hypothalamus. Grain counts for these magnocellular neurons in normal unstressed cats were highest at one hour post infusion with a significant fall off by three hours. Uptake by the SON and PVN at one hour exceeded neighboring nuclear groups by a factor of 7 and 4 fold respectively. Electron microscopic autoradiographs from acutely dehydrated cats revealed the presence of emission grains in association with rough endoplasmic reticulum and large osmiophilic neurosecretory vesicles. In view of statistically significant uptake values and rapid turnover of H³-valine by SON and PVN in normal animals, coupled with emission tracks in direct association with underlying neurosecretory product in acutely dehydrated ones, it is speculated that valine may be an amino acid component of one or both of the neurophysins to which neurohypophyseal hormones are non-covalently linked.Supported by U.S.P.H.S. Grant NS 08171.U.S.P.H.S. Career Development Awardee K04 GM70001.The authors are deeply indebted to Dr. Finley P. Gibbs and Dr. Sandy Sorrentino, Jr. for their advice and assistance in statistically quantifying autoradiographic data.     

Über die Bildung der Augenpigmentgranula beiDrosophila v undcn nach Verfütterung von Ommochromvorstufen

Zusammenfassung Bei denDrosophila-Mutantenv undcn, die weder Ommochrom noch leere Pigmentgranula aufweisen, läßt sich durch Verfüttern von Kynurenin, bzw. 3-Hydroxy-kynurenin die Bildung von Pigmentgranula induzieren, die von den Granula des Wildtyps nicht zu unterscheiden sind. Ihr größter Durchmesser beträgt ca. 0,4 , sie sind von einer Membran umgeben und ihre Wachstumsgeschwindigkeit ist identisch.Messung der heranwachsenden Granula in proximalen und distalen Bereichen der Ommatidien erbrachten einen signifikanten Größenunterschied; dieser ist bereits 48 Std nach der Verpuppung erkennbar.

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On the formation of eye pigment granules after feeding ommochrome precursors toDrosophila v andcn

Summary In the mutantsv andcn ofDrosophila, which contain neither ommochrome pigment nor empty pigment granules, feeding of kynurenine or 3-hydroxy-kynurenine causes the formation of pigment granules which cannot be distinguished from wild type granules. Their larger diameter is about 0.4 , they are surrounded by a membrane, and their growth rate is identical.Measurement of growing pigment granules in proximal and more distal regions of the ommatidia has revealed a significant difference in size which can be recognized as early as 48 hours after pupation.

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Wir danken der Deutschen Forschungsgemeinschaft für die finanzielle Unterstützung, Herrn Dr. F. G. Barth, Herrn Prof. H. Altner und seinen Mitarbeitern, sowie Frl. H. Tscharntke für Einweisung und Hilfe in der EM-Technik, und Herrn Dr. F. Schwabl für seinen Rat bei der Auswertung der Messungen.     

The deoxyribonucleoside 5′-triphosphate (dATP and dTTP) pool in phytohemagglutinin-stimulated and non-stimulated human lymphocytes

The pool size of dATP and dTTP in human lymphocytes was studied in untreated and PHA-treated cells. Different methods of extracting the cellular content of dATP and dTTP have been investigated and extraction with 60% methanol was preferred. The pool size of dATP and dTTP in non-stimulated lymphocytes was about 0.2 and 0.05 pmoles/10⁶ cells, respectively. After treatment with PHA for about 50 h the dATP and dTTP pools reached peak values representing increases in the pools of 20 and 170 fold, respectively. The variation in the pool sizes during transformation was paralleled by the variation of the rate of incorporation of labeled deoxy-thymidine into cellular DNA.     

Photoreversion und Photoprotektion bei UV-induzierten Mutationen des nichtphotoreaktivierbaren Bacteriums E.coli phr?

Summary Stationary phase cells of strain phr^–/MC 2 ofE. coli are not photoreactivable but the frequency of UV-induced mutations to low Streptomycine-resistance (S 3, 3/ml) is decreased strongly by illumination with light of fluorescence tubes (310 to 500 nm) after UV-irradiation. Also dark-reversion (DRM) of these mutations due to keeping UV-irradiated cells in saline is observed. Illumination before UV-irradiation decreases the frequency of the mutations (photoprotection against mutation=PPM) to the same extent as the combined action of photoreversion (PRM) and DRM. The lag-phase of cell division is prolonged strongly by illumination from 80 min without light to 150 min by the light-dose of highest activity. The additional lag is nearly the same if the illumination is done before, after or without UV-irradiation; this lag is about additive to the small lag caused by UV. Pre-illumination of the stationary-phase cells does not cause photoprotection against killing (PP), it even decreases the survival after high UV-doses. The observations support the hypothesis that PRM in this strain may be indirect, i.e. caused by the light-induced additional division lag which enhances the dark repair of UV-premutations. Also spontaneous premutations which are apparently present in the stationary-phase cells seem to be influenced by the light in this way.     

In memoriam. J. Mayo Greenberg (1922–2001)

Origins of Life and Evolution of Biospheres -     

Evaluation of the probiotics Bacillus subtilis and Lactobacillus plantarum bioencapsulated in Artemia nauplii against vibriosis in European sea bass larvae (Dicentrarchus labrax, L.)

Two potential probiotics Bacillus subtilis and Lactobacillus plantarum were evaluated for use in aquaculture as preventive measures against vibriosis. In vitro evaluation of the probiotics using co-culture assays with the pathogen Vibrio anguillarum and testing for the production of antibacterial substances showed the presence of antagonism and confirmed the production of antibacterial substances. Both potential probiotics were administered to the live fish feed Artemia franciscana nauplii, offering protection against a subsequent challenge of the nauplii with the fish pathogen V. anguillarum, with best survival rates of the nauplii and the most efficient protection offered by B. subtilis. Nauplii enriched with B. subtilis were further used to evaluate the protection of sea bass larvae against vibriosis. The untreated group of fish challenged with V. anguillarum presented low survival of 36.7 %, while the fish treated with nauplii enriched with the probiotic B. subtilis showed significantly increased survival rates of 86.7 % after challenge with the pathogen. The survival of healthy unchallenged fish treated with the probiotic was not significantly different from control unchallenged fish (90-94 %). Our results indicate that B. subtilis is a probiotic suitable to be used for the prevention of vibriosis in fish larvae and can be safely administered through their live feed Artemia nauplii.     

Conjugates of 5-isoquinolinesulfonylamides and oligo-D-arginine possess high affinity and selectivity towards Rho kinase (ROCK)

In the present work, conjugates of 5-isoquinolinesulfonylamides and D-arginine-rich peptides were developed into highly potent inhibitors for basophilic protein kinases. Based on Hidaka's inhibitor H9, a generic fluorescent probe ARC-1083 was constructed possessing subnanomolar dissociation constant towards several kinases of the AGC-group. Thereafter, Hidaka's inhibitor HA1077 or Fasudil was conjugated with oligo-D-arginine resulting in the compound ARC-3002 revealing high affinity towards ROCK-II (K(d)=20 pM) and over 160-fold selectivity compared to PKAc.