Quirks of dye nomenclature. 1. Evans blue

The history, origin, identity, chemistry and use of Evans blue dye are described along with the first application to staining by Herbert McLean Evans in 1914. In the 1930s, the dye was marketed under the name, Evans blue dye, which was profoundly more acceptable than the ponderous chemical name.     

The identification of a shared immunogen present in the salivary glands and gut of ixodid and argasid ticks

The identification of a 70-kDa immunogen present in salivary gland extracts of several ixodid species, namelyHyalomma truncatum (sweating-sickness-inducing (SS+) and non-inducing (SS-) strains),Hyalomma marginatum. rufipes andRhipicephalus evertsi evertsi, is reported. The immunogen was identified by Western blots using a monoclonal antibody of the IgM isotype directed against a 70-kDa immunogen present in the salivary glands of (SS-) femaleH. truncatum ticks. Cross-reactivity with the gut of unfed adult ixodid ticks,Amblyomma hebraeum, Rhipicephalus simus simus, R. evertsi evertsi, Rhipicentor nuttali, H.m. rufipes, and salivary glands of adult argasid species,Ornithodoros savignyi andOrnithodoros moubata, was demonstrated using ELISA.     

Temperature-dependent membrane fatty acid and cell physiology changes in coccoid forms of Campylobacter jejuni.

The effect of temperature and the availability of nutrients on the transition of spiral Campylobacter jejuni cells to coccoid forms was investigated. Ageing of spiral C. jejuni cells in either nutrient-poor or nutrient-rich environments resulted in the formation of nonculturable coccoid cells at 4, 12, and 25 degrees C after different periods, with the cells incubated at 4 degrees C in nutrient-deficient media remaining culturable the longest. To study the phenomenon, ATP levels, protein profiles, and fatty acid compositions were monitored under conditions where the transition from spiral to coccoid cells occurred. During storage, the levels of intracellular ATP were highest in cells incubated at low temperatures (4 and 12 degrees C) and remained constant after a small initial decrease. During the transformation from spiral to coccoid forms, no alteration in protein profiles could be detected; indeed, inhibition of protein synthesis by chloramphenicol did not influence the transition. Furthermore, DNA damage by gamma irradiation had no effect on the process. Membrane fatty acid composition of cocci formed at low temperatures was found to be almost identical to that of spiral cells, whereas that of cocci formed at 25 degrees C was clearly different. Combining these results, it is concluded that the formation of cocci is not an active process. However, distinctions between cocci formed at different temperatures were observed. Cocci formed at 4 degrees C show characteristics comparable to those of spirals, and these cocci may well play a role in the contamination cycle of C. jejuni.(ABSTRACT TRUNCATED AT 250 WORDS)     

Characterization of Pyrenophora Isolates Associated with Spot and Net Type Lesions on Barley in South Africa

Single-spored isolates of Pyrenophora associated with spot and net type net blotch of barley were compared using total DNA banding patterns, morphological and cultural characteristics, symptomatology and mating studies. Isolates of spot and net type net blotch were found to vary regarding conidium length and cultural growth rate. Mating studies among and between ascospore, spot and net type isolates proved unsuccessful under the conditions studied. Total DNA polymorphisms of the net spot and ascospore isolates digested with the restriction enzymes HpaII and HaeIII showed that the isolates have similar banding patterns. Random amplified polymorphic DNA (RAPD) showed that the banding patterns of the spot and net type isolates were again similar but were distinct from outgroups such as P. semeniperda and P. triticirepentis. The homology in DNA banding patterns of local isolates indicated that the difference in conidium length is insufficient to separate them as two species. It is concluded that spot and net type isolates occurring in South Africa belong to P. teres. Therefore spot type lesions are caused by P. teres f. sp. maculata and not by P. japonica as reported previously.     

Plasmodium berghei: the application of cultivation and purification techniques to molecular studies of malaria parasites

Species of malaria parasites that infect rodents provide models for the study of the biology of malaria parasites that infect humans. In this article, Chris Janse and Andy Waters describe some of the recent advances in the cultivation and purification methodology of one of these species, Plasmodium berghei. The improvement of these techniques, and the increasing knowledge about the molecular biology of P. berghei enhance the value of this particular rodent model for the investigation of many aspects of the biology of Plasmodium.     

Comparative studies of lignin peroxidases and manganese-dependent peroxidases produced by selected white rot fungi in solid media

Abstract The effect of various incubation conditions and media composition on ligninolytic activity by selected strains of white-rot fungi was determined in solid media. When compared to conventional methods using liquid media or woody substrates, this method is fast, simple and also quantitative. Manganese-dependent peroxidase was easily detected in all strains studied. However, detection of lignin peroxidase required optimisation of both growth medium and enzyme assay conditions. Using this method, we showed that the role of nitrogen and oxygen in ligninolytic activity varies and that conditions must be optimised for each individual even within the same species. Furthermore, several white rot fungi produced manganesedependent peroxidase during the primary growth phase. Keywords: Manganese-dependent peroxidase; Lignin peroxidase; White rot fungus     

A physical map of the Thinopyrum-derived Lr19 translocation.

Twenty-nine lines with deletions in the Lr19 ('Indis') translocated chromosome segment were used to physically map three Thinopyrum RFLP loci as well as the Sr25 and Sd1 loci. From the data, the relative locations of marker loci on the translocation were determined as: Sd1, Xpsr165, Xpsr105, Xps129, Lr19, Wsp-D1, Sr25/Y. The data confirmed the reported homoeology between the Lr19 segment and chromosome arm 7DL of wheat. Also, it seems that the Lr19 translocation in 'Indis' is very similar to the Lr19 segment in the T4 source and that the former may not derive from Thinopyrum distichum. Key words : deletion mapping, leaf rust resistance.     

ALS/FTD‐associated FUS activates GSK‐3β to disrupt the VAPB–PTPIP51 interaction and ER–mitochondria associations

Defective FUS metabolism is strongly associated with amyotrophic lateral sclerosis and frontotemporal dementia (ALS/FTD), but the mechanisms linking FUS to disease are not properly understood. However, many of the functions disrupted in ALS/FTD are regulated by signalling between the endoplasmic reticulum (ER) and mitochondria. This signalling is facilitated by close physical associations between the two organelles that are mediated by binding of the integral ER protein VAPB to the outer mitochondrial membrane protein PTPIP51, which act as molecular scaffolds to tether the two organelles. Here, we show that FUS disrupts the VAPB–PTPIP51 interaction and ER–mitochondria associations. These disruptions are accompanied by perturbation of Ca²⁺ uptake by mitochondria following its release from ER stores, which is a physiological read‐out of ER–mitochondria contacts. We also demonstrate that mitochondrial ATP production is impaired in FUS‐expressing cells; mitochondrial ATP production is linked to Ca²⁺ levels. Finally, we demonstrate that the FUS‐induced reductions to ER–mitochondria associations and are linked to activation of glycogen synthase kinase‐3β (GSK‐3β), a kinase already strongly associated with ALS/FTD.