Consequences of concurrent Ascaridia galli and Escherichia coli infections in chickens

   

Three experiments were carried out to examine the consequences of concurrent infections with Ascaridia galli and Escherichia coli in chickens raised for table egg production. Characteristic pathological lesions including airsacculitis, peritonitis and/or polyserositis were seen in all groups infected with E. coli. Furthermore, a trend for increased mortality rates was observed in groups infected with both organisms which, however, could not be confirmed statistically. The mean worm burden was significantly lower in combined infection groups compared to groups infected only with A. galli. It was also shown that combined infections of E. coli and A. galli had an added significant negative impact on weight gain.     

The evolutionary radiation of Arvicolinae rodents (voles and lemmings): relative contribution of nuclear and mitochondrial DNA phylogenies

Background  

Mitochondrial and nuclear genes have generally been employed for different purposes in molecular systematics, the former to resolve relationships within recently evolved groups and the latter to investigate phylogenies at a deeper level. In the case of rapid and recent evolutionary radiations, mitochondrial genes like cytochrome b (CYB) are often inefficient for resolving phylogenetic relationships. One of the best examples is illustrated by Arvicolinae rodents (Rodentia; Muridae), the most impressive mammalian radiation of the Northern Hemisphere which produced voles, lemmings and muskrats. Here, we compare the relative contribution of a nuclear marker – the exon 10 of the growth hormone receptor (GHR) gene – to the one of the mitochondrial CYB for inferring phylogenetic relationships among the major lineages of arvicoline rodents.     

Threading bis-intercalation of a macrocyclic bisacridine at abasic sites in DNA: nuclear magnetic resonance and molecular modeling study

The macrocyclic bisacridine (CBA) has been reported previously to specifically recognize single-stranded nucleic acid structures, especially DNA hairpins. The binding of the drug with an abasic site-containing oligonucleotide, was investigated by (1)H NMR and molecular modeling. We have used a DNA undecamer, the d(C(1)G(2)C(3)A(4)C(5)X(6)C(7)A(8)C(9)G(10)C(11)) x d(G(12)C(13)G(14)T(15)G(16)T(17)G(18)T(19)G(2)(0)C(21)G(22)) duplex in which the X residue is a stable analogue of the abasic site [3-hydroxy-2-(hydroxymethyl) tetrahydrofuran]. Analysis of the NMR data reveals that the bisacridine molecule forms two different intercalation complexes in a 80/20 (+/- 10) ratio. For the major complex, a molecular modeling study was performed guided by nineteen intermolecular drug-DNA restraints, determined from NOESY spectra. In this model, the ligand interacts in the threading binding mode with an acridine ring intercalated between the C(7)-A(8) and T(15)-G(16) base pairs, while the other acridine ring resides in the abasic pocket. The two linker chains are positioned in the minor and in the major groove, respectively. A comparable study was performed to evaluate the interaction of CBA with the parent unmodified duplex in which X(6) was replaced by an adenine residue. No complex formation was observed when operating in identical conditions. This shows the selective binding of CBA to the abasic site and its potential interest to target the abasic site lesion.     

Aryldiazomethane derivatives as reagents for site specific labeling of nucleic acids at phosphate

An efficient and direct labeling method based on direct alkylation of nucleic acids at phosphates by aryldiazomethane derivatives is described.     

Aryldiazomethanes for universal labeling of nucleic acids and analysis on DNA chips

DNA and RNA labeling and detection are key steps in nucleic acid-based technologies, used in medical research and molecular diagnostics. We report here the synthesis, reactivity, and potential of a new type of labeling molecule, m-(N-Biotinoylamino)phenylmethyldiazomethane (m-BioPMDAM), that reacts selectively and efficiently with phosphates in nucleotide monomers, oligonucleotides, DNA, and RNA. This molecule contains a biotin as detectable unit and a diazomethyl function as reactive moiety. We demonstrate that this label fulfills the requirements of stability, solubility, reactivity, and selectivity for hybridization-based analysis and especially for detection on high-density DNA chips.     

The abundance of additional N-acetyllactosamine units in N-linked tetraantennary oligosaccharides of human Tamm-Horsfall glycoprotein is a donor-specific feature

Previously, treatment of Tamm-Horsfall glycoprotein (THp) from different donors with endo-beta-galactosidase has been shown to liberate a tetra- and a Sd(a)-active pentasaccharide, concluding the presence of N-linked carbohydrate chains containing additional N - acetyllactosamine units. These type of oligosaccharides were not found in a detailed structure elucidation of the carbohydrate moiety of THp of one male donor, suggesting a donor-specific feature for these type of structures. Therefore, THp was isolated from four healthy male donors and each subjected to endo-beta-galactosidase treatment in order to release these tetra- and Sd(a)-active pentasaccharide. Differences were observed in the total amount of released tetra- and Sda-active pentasaccharide of the used donors (42, 470, 478, 718 microg/100 mg THp), indicating that the presence of repeating N-acetyllactosamine units incorporated into the N-glycan moiety of THp is donor specific. Furthermore, a higher expression of the Sd(a) determinant on antennae which display N-acetyllactosamine elongation was observed, suggesting a better accessibility for the beta-N-acetylgalactosaminyltransferase. In order to characterize the N-glycans containing repeating N- acetyllactosamine units, carbohydrate chains were enzymatically released from THp and isolated. The tetraantennary fraction, which accounts for more than 33% of the total carbohydrate moiety of THp, was used to isolate oligosaccharides containing additional N - acetyllactosamine units. Five N-linked tetraantennary oligosaccharides containing a repeating N-acetyllactosamine unit were identified, varying from structures bearing four Sd(a) determinants to structures containing no Sd(a) determinant (see below). One compound was used in order to specify the branch location of the additional N- acetyllactosamine unit, and it appeared that only the Gal-6' and Gal-8' residues were occupied by a repeating N -acetyllactosamine unit.