EST based phylogenomics of Syndermata questions monophyly of Eurotatoria

Background  

The metazoan taxon Syndermata comprising Rotifera (in the classical sense of Monogononta+Bdelloidea+Seisonidea) and Acanthocephala has raised several hypotheses connected to the phylogeny of these animal groups and the included subtaxa. While the monophyletic origin of Syndermata and Acanthocephala is well established based on morphological and molecular data, the phylogenetic position of Syndermata within Spiralia, the monophyletic origin of Monogononta, Bdelloidea, and Seisonidea and the acanthocephalan sister group are still a matter of debate. The comparison of the alternative hypotheses suggests that testing the phylogenetic validity of Eurotatoria (Monogononta+Bdelloidea) is the key to unravel the phylogenetic relations within Syndermata. The syndermatan phylogeny in turn is a prerequisite for reconstructing the evolution of the acanthocephalan endoparasitism.     

Ultrastructural and morphometric aspects of the juxtaglomerular apparatus in the monkey kidney

Summary The authors describe the ultrastructure of the juxtaglomerular apparatus in five adult male Cebus apella monkeys and communicate morphometric data of the macula densa.In comparison with several species of rodents examined before, the macula cells of the monkey contain many more mitochondria and possess a particularly thick basal membrane. The relative volume of the nuclei is slightly smaller than in rodents.The Goormaghtigh cells of the monkey resemble those of the other animals investigated.The epithelioid (or juxtaglomerular) cells do not contain secretory granules. This observation reminds one of the behavior of the epithelioid cells of guinea pigs.Dedicated to Professor Dr. med. G. Petry (Marburg/Lahn) on the occasion of his 65th birthdayThe authors wish to thank Professor Dr. G. Peters, Head of the Institute of Pharmacology, and Professor Dr. F. Roch-Ramel for kindly having provided the monkey kidneys     

p87 and p101 Subunits Are Distinct Regulators Determining Class IB Phosphoinositide 3-Kinase (PI3K) Specificity

Class I_B phosphoinositide 3-kinase γ (PI3Kγ) comprises a single catalytic p110γ subunit, which binds to two non-catalytic subunits, p87 or p101, and controls a plethora of fundamental cellular responses. The non-catalytic subunits are assumed to be redundant adaptors for Gβγ enabling G-protein-coupled receptor-mediated regulation of PI3Kγ. Growing experimental data provide contradictory evidence. To elucidate the roles of the non-catalytic subunits in determining the specificity of PI3Kγ, we tested the impact of p87 and p101 in heterodimeric p87-p110γ and p101-p110γ complexes on the modulation of PI3Kγ activity in vitro and in living cells. RT-PCR, biochemical, and imaging data provide four lines of evidence: (i) specific expression patterns of p87 and p101, (ii) up-regulation of p101, providing the basis to consider p87 as a protein forming a constitutively and p101 as a protein forming an inducibly expressed PI3Kγ, (iii) differences in basal and stimulated enzymatic activities, and (iv) differences in complex stability, all indicating apparent diversity within class I_B PI3Kγ. In conclusion, expression and activities of PI3Kγ are modified differently by p87 and p101 in vitro and in living cells, arguing for specific regulatory roles of the non-catalytic subunits in the differentiation of PI3Kγ signaling pathways.     

BlastR--fast and accurate database searches for non-coding RNAs

We present and validate BlastR, a method for efficiently and accurately searching non-coding RNAs. Our approach relies on the comparison of di-nucleotides using BlosumR, a new log-odd substitution matrix. In order to use BlosumR for comparison, we recoded RNA sequences into protein-like sequences. We then showed that BlosumR can be used along with the BlastP algorithm in order to search non-coding RNA sequences. Using Rfam as a gold standard, we benchmarked this approach and show BlastR to be more sensitive than BlastN. We also show that BlastR is both faster and more sensitive than BlastP used with a single nucleotide log-odd substitution matrix. BlastR, when used in combination with WU-BlastP, is about 5% more accurate than WU-BlastN and about 50 times slower. The approach shown here is equally effective when combined with the NCBI-Blast package. The software is an open source freeware available from www.tcoffee.org/blastr.html.     

The Staphylococcus aureus mec determinant comprises an unusual cluster of direct repeats and codes for a gene product similar to the Escherichia coli sn-glycerophosphoryl diester phosphodiesterase.

The DNA sequence located between mecA, the gene that codes for penicillin-binding protein PBP2', and insertion sequence-like element IS431mec has been termed hypervariable because of its length polymorphism among different staphylococcal isolates. We sequenced and characterized the hypervariable region of the methicillin resistance determinant (mec) isolated from Staphylococcus aureus BB270. Within the 2,040-bp hypervariable region, we identified an unusual accumulation of long direct repeats. Analysis of the DNA sequence revealed a minimal direct repeat unit (dru) of 40 bp which was repeated 10 times within 500 bp. The dru sequences are responsible for the length polymorphism of mec. Moreover, we identified an open reading frame that codes for 145 amino acids (ORF145), whose deduced amino acid sequence showed 57% amino acid sequence similarity to the N terminus of the glycerophosphoryl diester phosphodiesterase (UgpQ) of Escherichia coli.     

Effect of cell phone radiofrequency radiation on body temperature in rodents: Pilot studies of the National Toxicology Program's reverberation chamber exposure system

Radiofrequency radiation (RFR) causes heating, which can lead to detrimental biological effects. To characterize the effects of RFR exposure on body temperature in relation to animal size and pregnancy, a series of short‐term toxicity studies was conducted in a unique RFR exposure system. Young and old B6C3F1 mice and young, old, and pregnant Harlan Sprague‐Dawley rats were exposed to Global System for Mobile Communication (GSM) or Code Division Multiple Access (CDMA) RFR (rats = 900 MHz, mice = 1,900 MHz) at specific absorption rates (SARs) up to 12 W/kg for approximately 9 h a day for 5 days. In general, fewer and less severe increases in body temperature were observed in young than in older rats. SAR‐dependent increases in subcutaneous body temperatures were observed at exposures ≥6 W/kg in both modulations. Exposures of ≥10 W/kg GSM or CDMA RFR induced excessive increases in body temperature, leading to mortality. There was also a significant increase in the number of resorptions in pregnant rats at 12 W/kg GSM RFR. In mice, only sporadic increases in body temperature were observed regardless of sex or age when exposed to GSM or CDMA RFR up to 12 W/kg. These results identified SARs at which measurable RFR‐mediated thermal effects occur, and were used in the selection of exposures for subsequent toxicology and carcinogenicity studies. Bioelectromagnetics. 39:190–199, 2018. © 2018 The Authors. Bioelectromagnetics Published by Wiley Periodicals, Inc.     

A propos des ≪chloride cells≫ dans l'épithélium des lamelles branchiales du poisson rouge

Résumé L'ultrastructure des lamelles branchiales et spécialement celle des chloride cells du poisson rouge (Carassius aureus) a été étudiée. Nous avons constaté que du matériel amorphe floconneux, faiblement adiélectronique était attaché aux endroits des creux apicaux. Afin de préciser la nature de ce matériel, nous avons étudié ces structures au microscope électronique avec les techniques suivantes: acide periodique méthènamine d'argent, colorations au fer colloïdal et au bleu d'alcian. Après la réaction à l'acide periodique méthènamine d'argent, de fines précipitations aux endroits des creux apicaux, correspondant au matériel floconneux visible après la fixation au glutaraldéhyde tétroxyde d'osmium, étaient visibles. La coloration au bleu d'alcian révélait des particules fortement colorées formant un film plus ou moins continu à la surface libre des lamelles, sauf aux endroits oò les chloride cells sont en contact avec la surface. Là et notamment dans les 2reux apicaux, du matériel légèrement granuleux, de faible densité, faisait une couche assez épaisse attachée à la membrane cellulaire. Tenant compte des résultats d'autres auteurs et de nos propres observations, nous considérons que la plus grande partie du matériel se trouvant à la surface des chloride cells, et particulièrement dans les creux apicaux, est de type glycoprotéique.

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The ultrastructure of the chloride cells in the gill epithelium of the goldfish

Summary The ultrastructure of the secondary lamellae of the gills and especially that of the chloride cells of Carassius aureus was studied. We found an amorphous, flakey, slightly adielectronic material in the areas of the apical pits. In order to determine the nature of this material, we studied these structures electronmicroscopically applying the periodic acid silver methenamine, colloidal iron and alcian blue methods. The periodic acid silver methenamine reaction, resulted in finely dispersed precipitations which were deposited in the areas of the apical pits and which correspond to the flakey material seen in the ordinary electron micrographs. The alcian blue method reveales strongly stained particles which form a more or less continuous film on the free surface of the lamellae, interrupted only at the level of the chloride cells. In these areas, notably within the apical pits, a rather thick layer of finely granular low-density material is attached to the plasma membrane. In taking into account other studies performed on this subject, as well as our own observations, we consider the material found on the surface of the chloride cells and particularly within their apical pits to be predominantly of glycoproteinous nature.

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Dédié à Monsieur le Professeur Dr Ernst Horstmann, Hambourg, à l'occasion de son soixantième anniversaire.     

M protein (M1) of influenza virus: antigenic analysis and intracellular localization with monoclonal antibodies.

A panel of 16 monoclonal antibodies recognizing M protein (M1) of influenza virus was generated. Competition analyses resulted in localization of 14 monoclonal antibodies to three antigenic sites. Three monoclonal antibodies localized to site 1B recognized a peptide synthesized to M1 (residues 220 to 236) with enzyme-linked immunosorbent assay titers equivalent to or greater than that seen with purified M1; therefore, site 1B is located near the C terminus of M1. Sites 2 and 3 localize to the N-terminal half of M1. Antigenic variation of M proteins was seen when the monoclonal antibodies were tested against 14 strains of type A influenza viruses. Several monoclonal antibodies showed specific recognition of A/PR/8/34 and A/USSR/90/77 M proteins and little or no reactivity for all other strains tested. Immunofluorescence analysis with the monoclonal antibodies showed migration of M protein to the nucleus during the replicative cycle and demonstrated association of M protein with actin filaments in the cytoplasm. Use of a vaccinia virus recombinant containing the M-protein gene demonstrated migration of M protein to the nucleus in the absence of synthesis of gene products from other influenza virus RNA segments.