Examination through a principal component analysis of the phosphorus exchanges between sediments and water in trophically different reservoirs

Phosphorus exchange at the sediment-water interface coupled with several parameters were assessed in several reservoirs with geologically different catchment basins and different trophic status in Morocco and France.The results showed that these exchanges were regulated by a combination of factors: physical chemical variability of the environment, the geological composition of catchment basins and the trophic status of the lake.In the hypereutrophic Villerest, iron-bound phosphorus is the major form of phosphorus trapped by the sediment whereas, in Moroccan reservoirs, calcium-bound phosphorus prevailed.We suggest that a drastic control of phosphorus inputs into the waters must be done through a large program of dephosphatization of tributaries to avoid Microcystis aeruginosa bloom formation in Villerest (Aleya et al., 1993) and calcium-bound phosphorus dissociation in Moroccan reservoirs with upward release of bioavailable phosphorus.

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Résumé Les échanges de phosphore au niveau de l'interface eau-sédiment couplés á la distribution temporelle de divers éléments chimiques et biologiques ont été étudiés dans divers réservoirs de niveaux trophiques différents, au Maroc et en France.Nos résultats mettent clairement en évidence une influence directe de l'environnement physico-chimique, de la nature géologique des bassins versants et de l'état trophique du lac sur la dynamique du phosphore au sein de cette interface.De plus, il apparait que dans le lac hypereutrophe de Villerest (Roanne, France), le phosphore est majoritairement complexé au fer alors que dans les retenues marocaines, ce sont les complexes phosphore-calcium qui prédominent.Nous préconisons un contrôle drastique des apports en phosphore á travers l'installation et la multiplication d'unités de déphosphatation afin d'éviter d'une part, la prolifération massive de la Cyanobactérie Microcystis aeruginosa á Villetest (Aleya et al., 1994) et d'autre part la dissociation des complexes phhosphore-calcium au sein des retenues marocaines avec libération de phosphore biodisponible.

     

Role of Drosophila gene dunc-115 in nervous system

Axonal guidance signals are transduced through growth cone surface receptors to the interior leading to changes of actin dynamics and actin binding proteins, which are critical in determining the outcome of actin cytoskeleton reorganization. We report here the characterization of the Drosophila actin binding protein abLIM/Unc-115 homolog Dunc-115 and its role in the nervous system. Three Dunc-115 isoforms are identified as Dunc-115L, M and S, respectively. While Dunc-115L is a canonical homolog of Unc-115 with four LIM domains and one villin headpiece domain, Dunc-115M and S are novel isoforms without counterparts in other species. Our molecular modeling shows Dunc-115L is likely to bind to actin. Mutant analysis reveals that Dunc-115 is involved in axonal projection in both the visual and central nervous system.     

Characteristic of tumors developed after transplantation of transgenic GFP-positive C57BL/6 mice bone-marrow mesenchymal stem cells to mdx mice muscle

The purpose of the study was the morphological and histochemical characteristics of differentiation of tumors developed after transplantation of GFP-positive mesenchymal bone-marrow stem cells (MSC) of transgenic mice C57BL/6 into M. quadriceps femoris of mdx mice. The tumors occurred only after transplantation of MSCs of 43-45th passages and did not arise after transplantation of MSCs of the 15th passage. No tumors developed also after transplantation of MSCs of 43-45th passages into muscle of C57BL/6 mice. The average weight of tumors appeared in 4 mdx mice studied was 1.3 +/- 0.5 g. All four tumors were classified as mesenchymomas because they originated from mesenchymal stem cells. Most of the periphery of the tumors was classified as fibrosarcomas with mitotic index 0.9 +/- 0.1%. The central parts of tumors had areas with epithelial like morphology of cells. Such cells showed positive reactivity for alcyan blue staining at pH 2.5, which indicated chondrocyte nature of the cells. No mitosis was observed in epithelial like cells. In the tumors, there were also areas with bone trabeculae containing megacaryocytes and foci of myeloid and erythrocyte hematopoiesis. There were also areas with neuronal and glial cells, and accumulations of adipocytes. One of the tumors was classified as a round cells sarcoma. The observed types of tumor cell differentiation in vivo were in accordance with described in literature types of MSCs differentiation after induction in vitro with special inductors. The spectrum of in vivo differentiation of transgenic GFP-positive MSCs after transplantation to mdx mice was broader than the spectrum of in vivo differentiation of transfected or transformed in vitro adult MSCs after transplantation to immunodeficient mice and mdx mice.     

Molecular phylogeny of three ambiguous ciliate genera: Kentrophoros,Trachelolophos and Trachelotractus (Alveolata,Ciliophora)

Gao, S., Strüder‐Kypke, M.C., Al‐Rasheid, K.A.S., Lin, X. & Song, W. (2010). Molecular phylogeny of three ambiguous ciliate genera: Kentrophoros, Trachelolophos and Trachelotractus (Alveolata, Ciliophora).—Zoologica Scripta, 39, 305–313. Very few molecular studies on the phylogeny of the karyorelictean ciliates have been carried out because data of this highly ambiguous group are extremely scarce. In the present study, we sequenced the small subunit ribosomal RNA genes of three morphospecies representing two karyorelictean genera, Kentrophoros, Trachelolophos, and one haptorid, Trachelotractus, isolated from the South and East China Seas. The phylogenetic trees constructed using Bayesian inference, maximum likelihood, maximum parsimony and neighbor‐joining methods yielded essentially similar topologies. The class Karyorelictea is depicted as a monophyletic clade, closely related to the class Heterotrichea. The generic concept of the family Trachelocercidae is confirmed by the clustering of Trachelolophos and Tracheloraphis with high bootstrap support; nevertheless, the order Loxodida is paraphyletic. The transfer of the morphotype Trachelocerca entzi Kahl, 1927 to the class Litostomatea and into the new haptorid genus Trachelotractus, as suggested by previous researchers based on morphological studies, is consistently supported by our molecular analyses. In addition, the poorly known species Parduczia orbis occupies a well‐supported position basal to the Geleia clade, justifying the separation of these genera from one another.     

Homo-C-nucleoside analogs III. Studies on the base-catalyzed dehydrative cyclization of 4-(d-manno-pentitol-1-yl)-2-phenyl-2H-1,2,3-triazole

Treatment of 4-(d-manno-pentitol-1-yl)-2-phenyl-2H-1,2,3-triazole with one molar equivalent of 2,4,6-triisopropylbenzenesulfonyl chloride (TIBSCl) in pyridine solution afforded the homo-C-nucleoside analog; 4-(2,5-anhydro-d-manno-pentitol-1-yl)-2-phenyl-2H-1,2,3-triazole in 54% yield and 4-(α-d-arabinopyranosyl)-2-phenyl-2H1,2,3-triazole analog in 3% yield. The 4-(5-O-triisopropylbenzenesulfonyl)-d-manno-pentitol-1-yl)-2-phenyl-2H-1,2,3-triazole analog was isolated as an intermediate and identified as its tetra-O-acetyl derivative. The 4-(5-chloro-5-deoxy-d-manno-pentitol-1-yl)-2-phenyl-2H-1,2,3-triazole analog was isolated as a byproduct. The structure and anomeric configuration of the products were determined by acylation, NMR spectroscopy, and mass spectrometry.     

Delivery of CRISPR/Cas Components into Higher Plant Cells for Genome Editing

Russian Journal of Plant Physiology - CRISPR/Cas genome editing of plants is realized in three basic variants, including knockout mutations as indels, insertion of alien DNA fragments, and base...     

Molecular genetics of met 17 and met 25 mutants of Saccharomyces cerevisiae: intragenic complementation between mutations of a single structural gene

Summary A method for transposon mutagenesis in Azospirillum lipoferum 29708 is reported with transposon Tn5. The suicide plasmid pSUP2021 was used to deliver Tn5 in A. lipoferum using Escherichia coli SM10 as the donor. Neomycin-resistant transconjugants were detected at a frequency of 6x10^-6 per recipient. Different types of mutants were isolated, e.g. auxotrophic, coloured, IAA-negative, and IAA-overproducers. Among the auxotrophic mutants, cysteine and methionine requirers prevailed. Random Tn5-insertion with only one copy per mutant was demonstrated by Southern blotting and hybridization. Tn5-induced mutants are relatively stable, with reversion rates of 2–20×10^-8. A gene which is a part of the carotenoid pathway is closely linked to the histidine genes. The existence of two pathways for IAA production in A. lipoferum is discussed.     

Percutaneous closure of an adult patent ductus arteriosus

A 23-year-old asymptomatic male was referred to our outpatient clinic because of an incidentally discovered grade III continuous machinery murmur at the third intercostal space on the left sternal edge. The echocardiography showed the presence of a patent ductus arteriosus (PDA).     

The hormonal and genetic effects induced by an irradiation in small dozes at Tradescantia (a clone 02)

The purpose of the present work was studying the possible interrelation of the hormonal status of plants and size of the genetic effects induced by an irradiation in small dozes. The frequency of somatic mutations in strings Tradescantia (a clone 02) at an irradiation in dozes up to 28 cGy was estimated. Influence radiations in a range from background up to 28 cGy on the maintenance in inflorescences Tradescantia (a clone 02) the basic groups of plant hormones is investigated: abscisic acid, cytokinin, auxin and gibberellin A3. It is shown, that small dozes of an irradiation cause extremely radical changes of hormonal balance in fabrics of inflorescences Tradescantia. Received results are discussed with attraction of the data on influence phytohormones on kinetics a cellular cycle.