Initiator RNA of discontinuous DNA synthesis in human lymphocytes

A short RNA covalently associated with nascent DNA has been isolated after synthesis in vitro with labeled ribonucleoside triphosphates and the removal of DNA by DNAase digestion. The RNA migrates in polyacrylamide gels or chromatographs on DEAE-Sephadex columns as a relatively discrete oligonucleotide 8–11 nucleotides in length. The RNA is associated primarily with nascent DNA with stoichiometry of approximately one per DNA chain. The RNA has a triphosphate group at the 5′ end and 2 or 3 deoxynucleotide residues at the 3′ end that are not removed by DNAase. These results further support a role for the RNA as an initiator of discontinuous DNA synthesis. Examination of sequences present at the 3′ end of the RNA using RNAase to effect transfer of ³²PO₄ from ³²P-labeled DNA to covalently attached RNA indicates that a diverse, rather than unique, set of sequences are present in the RNA.     

The monoclonal antibodies Elec-39, HNK-1 and NC-1 recognize common structures in the nervous system and muscles of vertebrates

The IgM monoclonal antibodies, Elec-39, HNK-1 and NC-1, recognize the same subset of Torpedo electric organ acetylcholinesterase (AChE). We show that they react against a glycosphingolipid (SGPG) containing a sulfated glucuronic acid (SGA). The three antibodies appear essentially identical in their specificity but differ in their affinity for the antigens. We have examined their binding in the CNS, nerves and muscles of several vertebrate species, at the optical and in some cases at the electron microscope level. All three antibodies label the same structures: they show diffuse staining around neuromuscular endplates and label the plasma membrane of the Schwann cells, surrounding the outer layer of myelin sheaths. In the adult rat CNS, the antibodies label certain defined structures, notably extracellular material in the habenula and in the CA2 layer of the hippocampus. In the cortex and cerebellum, they label the surface of neural processes and terminals apposed to large multipolar neurons and Purkinje cells, as well as membranous material contained in inclusions dispersed in the cytoplasm of these neurons. These localizations are consistent with the suggestion that the SGA-antigens may be involved in cellular interactions.     

Comparison of spatial scale variability of shoot density and epiphytic leaf assemblages of Halophila stipulacea and Cymodocea nodosa on the Eastern Coast of Tunisia

Abstract

A study was undertaken to compare the patterns of spatial variability, epiphytic percentage cover, and distribution of epiphytic fauna and flora between the two adjacent seagrasses Cymodocea nodosa and the invasive species Halophila stipulucea. Samples were taken at six stations separated by 600?m and exposed to different current conditions. The stations G2 and G5 were affected by a high current tide, while G4 was directly exposed to the northern marine currents. The station G3 was situated in the middle of a Posidonia oceanica bed and was less exposed to hydrodynamism, whereas the other stations were relatively protected. Results indicate that for both H. stipulacea and C. nodosa, shoot density and epiphytic cover biomass decreased when exposed to high levels of hydrodynamic activity. In terms of epiphytic leaf assemblages, our results showed significant differences for the two host plants in their mean cover and for the six stations at the largest and smallest spatial scale. Our observations highlight the dominance of Rhodophyta and the low number of epiphytic species and the epiphytic cover on H. stipulacea compared to C. nodosa. In addition, results indicate the absence of two taxa Hydrozoans and Annelida in the epiphytic assemblage of H. stipulacea leaves.     

Lactobacillus salivarius A3iob Reduces the Incidence of Varroa destructor and Nosema Spp. in Commercial Apiaries Located in the Northwest of Argentina

Lactobacillus salivarius A3iob was administered to productive colonies belonging to commercial apiaries of small beekeepers (around 30–50 hives each one), from four departments of the province of Jujuy (Argentina): Yala, Tilquiza, El Carmen, and Los Alisos. The incidence of Varroa destructor and Nosema spp., before and after winter, was monitored during 2 years of study (2014–2015). Depending on the geographical location of each apiary and the application time, a monthly dose of the bacteria (10⁵ CFU/mL) reduced the levels of varroasis between 50 and 80%. Interestingly, L. salivarius A3iob cells remitted the percentage of the mites to undetectable values in an apiary treated with flumethrin (at Yala, Yungas region).

On the other hand, the spore levels of Nosema spp. in the lactobacilli-treated colonies also depended on the apiary and the year of application, but a significant decrease was mainly observed in the post-winter period. However, at Rivera (El Carmen’s department), no significant changes were detected in both parameters.

These results obtained after 2 years of work suggest that delivering L. salivarius A3iob cells to the bee colonies can become a new eco-friendly tool to cooperate with the control of these bees’ pests.

     

Profiling and Identification of Small rDNA-Derived RNAs and Their Potential Biological Functions

Small non-coding RNAs constitute a large family of regulatory molecules with diverse functions. Notably, some small non-coding RNAs matched to rDNA have been identified as qiRNAs and small guide RNAs involved in various biological processes. However, a large number of small rDNA-derived RNAs (srRNAs) are usually neglected and yet to be investigated. We systematically investigated srRNAs using small RNA datasets generated by high-throughput sequencing, and found srRNAs are mainly mapped to rRNA coding regions in sense direction. The datasets from immunoprecipitation and high-throughput sequencing demonstrate that srRNAs are co-immunoprecipitated with Argonaute (AGO) proteins. Furthermore, the srRNA expression profile in mouse liver is affected by diabetes. Overexpression or inhibition of srRNAs in cultured cells shows that srRNAs are involved in various signaling pathways. This study presents a global view of srRNAs in total small RNA and AGO protein complex from different species, and demonstrates that srRNAs are correlated with diabetes, and involved in some biological processes. These findings provide new insights into srRNAs and their functions in various physiological and pathological processes.