Microarray genomotyping of key experimental strains of Neisseria gonorrhoeae reveals gene complement diversity and five new neisserial genes associated with Minimal Mobile Elements.

Background  

There are four widely used experimental strains of N. gonorrhoeae, one of which has been sequenced and used as the basis for the construction of a multi-strain, mutli-species pan-neisserial microarray. Although the N. gonorrhoeae population structure is thought to be less diverse than N. meningitidis, there are some recognized gene-complement differences between strains, including the 59 genes of the Gonococcal Genetic Island. In this study we have investigated the three experimental strains that have not been sequenced to determine the extent and nature of their similarities and differences.     

CHANGES IN CHEMICAL, SENSORY AND RHEOLOGICAL CHARACTERISTICS OF MANCHEGO CHEESES DURING RIPENING

Manchego cheese is a high-fat pressed ewe's-milk cheese made in Castilla-La Mancha (Spain) and produced by enzymatic coagulation. The minimum ripening time before marketing required by the Regulatory Board of the Manchego Cheese Appellation of Origin is 60 days.
This paper describes the physicochemical, proteolysis, sensory and texture characteristics of Manchego cheese, and the degree of homogeneity of cheeses made under the Manchego Appellation of Origin. The data gathered in this study indicate that sensory and instrumental analysis are useful tools for detecting changes in Manchego cheese during ripening. These changes were first detected by the instrumental analysis (2 months). The panelists detected differences after 4 months' ripening in all the factories. With physicochemical analysis, on the other hand, longer ripening times (6–8 months) are required before such changes become appreciated.     

Organelles involved in the synthesis and transport of hydroxyproline-containing glycoproteins in carrot root discs

Isopycnic sucrose density gradients of homogenates from carrot root tissue were analyzed radiochromatographically, radiochemically, and photometrically for the presence of hydroxyproline residues. Significant amounts were found in endoplasmic reticulum (ER), Golgi apparatus (GA) and plasma membrane (PM) fractions as designated by the presence of marker enzymes for these membranes. Some hydroxyproline-containing macromolecules could be detected in the soluble cytoplasm (cytosol) but this was interpreted as an artefact due to homogenization. Hydroxyproline-rich polymers can be released from a mixed ER/PM fraction by freezing and thawing in water. The PM-associated hydroxyproline polymer is suggested to be an arabinogalactan protein rather than cell wall extensin. Nevertheless, the polypeptides of both glycoproteins are considered as being synthesized at the ER and transported via the GA to the PM.Abbreviations BSA Bovine serum albumin - CCO cytochrome c-oxidase - CCR cytochrome c-reductase - DTT dithiothreitol - EDTA ethylene diaminotetracetic acid - ER endoplasmic reticulum - GA Golgi apparatus - GS I/II glucan synthetase I/II - IDP(ase) inosine diphosphat(ase) - PM plasma membrane - RNA ribonucleic acid - TCA trichloracetic acid - Tris tris-(hydroxymethyl)-aminomethane - UDPG uridine diphosphoglucose     

Fertilization envelope assembly in sea urchin eggs inseminated in Cl− deficient sea water: I. Morphological effects

Elevation and hardening of the fertilization envelope (FE) occur within 15 min following insemination of the sea urchin egg. When chloride ions were replaced in the media with various anion substitutes, including methyl sulfonate, nitrates, bromide, and isethionate, the fertilization envelope failed to harden and collapsed back to the surface of the egg of Lytechinus variegatus, L. pictus, and Strongylocentrotus purpuratus. At the light microscopy level, the collapse of the envelope was accompanied by a decrease in birefringence, compared with controls. When examined with electron microscopy, the FEs of eggs inseminated in reduced Cl^? solutions failed to transform from an amorphous layer into the more robust laminar structure observed around eggs incubated in normal sea water. Furthermore, in the case of S. purpuratus, the I-T transformation of the FE did not occur. When transfer of the inseminated eggs from the Cl^?-deficient sea water to normal sea water was carried out before 10 min elapsed, the envelope did not collapse, and the birefringence of the envelope was similar to that of controls. Partial envelope collapse was also observed in a dose-dependent manner, varying with the concentration of the Cl^? in the sea water solution. The results suggest that lack of Cl^? in the media may interfere with proper fertilization envelope assembly. Possible mechanisms, including proper incorporation of the cortical granule exudate into the nascent envelope structure, are discussed.     

On the induction of cup-shaped dictyosomes in suspension culturedAcer pseudoplatanus

Summary A variety of agents, including metabolic inhibitors, chelators and ionophores have been applied to suspension cultures ofAcer pseudoplatanus in an attempt at inducing cup-shaped dictyosomes. Only antipyrine was effective and then only after culturing the cells prior to treatment in sucrose-deficient medium. ATP measurements suggest a potential effect of antipyrine on energy metabolism. Both the ultrastructural effects and the reduction in ATP levels through antipyrine treatment are reversible.Abbreviations DMSO dimethylsulfoxide - DNP dinitrophenol - EDTA ethylene diaminotetraacetic acid - EGTA ethylene glycol-bis (2-aminoethyl)-tetraacetic acid - GDPH glucose-6-phosphate dehydrogenase - HIPES 2-4(2-hydroxyethyl)-piperyzine-(1)-ethynsulfonic acid - SHAM salicylhydroxamic acid